The whole point of travel clothing is that it is not 'run of the mill'. When choosing what to pack for a big trip, therefore, comfort, robustness and ease of care should be the prime considerations. The way it all fits into your luggage should be a high priority, too, since there is no point in packing garments that are heavy or bulky. Ease of care is also important. Naturally, the simplest way to travel lighter is to take fewer items of clothing, which means that what is taken should be as washable in a hotel hand basin as it is in a mountain stream. In most cases, synthetic fibres not only wash more easily, they dry more quickly, too. Personally, I have been a fan of the lightweight travel clothing (pioneered by Rohan) since it became available 20 years ago. It has the benefits of being both light and durable, and while cheap alternatives tend not to have reinforcing bar tacks stitched into the ends of the zippers or securing the belt loops and zipped security pockets (impossible to pick), I still recommend this style. You might not care to try it, but yes, a pair of Rohan's best-selling Bags trousers really does fit into a Coke can!

Local sensibilities

There are plenty of reasons why one should not want to draw undue attention to oneself while travelling. Inappropriate dress can cause unwanted attention when it is often preferable to blend in with the scenery - crossing borders, checking into hotels, even minding your own business waiting at railway stations. Yet often, when it comes down to it, being thin, tall and pale, I know I am going to stick out anyway. My advice is not to go over the top. Nobody expects me to wear a kilt when I go to Scotland (except perhaps for Burns Night), so dressing up in any kind of ethnic kit is likely to leave me looking pretty ridiculous.

Some years ago, DPM (disruptive pattern material) clothing was all the rage in outdoors circles, with everything from clothing to rucksacks sporting camouflage patterns in commando styles. And since the Gulf War, we've also seen a fashion in desert camouflage combat trousers. Great for a night out in Manchester, perhaps, but pretty stupid in Africa. I've even heard reports of DPM-clad backpackers in the Pyrenees being shot at by the local bandits.

Of course you may have to consider the way you are dressed in certain situations to avoid offending local sensibilities, or in order not to make yourself a target for muggers. There are times when common sense should also prevail. This generally means not exposing too much bare skin when it really is inappropriate (besides, see Sun protection, below), which will generally apply to women much more than men. Having said that, western style is prevalent all over the world, and there are few big towns and cities where you will not see the likes of Coca-Cola T-shirts and baseball caps. Out in the provinces, the situation may well be different. The best advice is simply to be guided by what you see around you.

The practical side of clothing

If we work on a system of layered clothing, you will find you can cater for just about every kind of climate from temperate to downright cold, with only a few adjustments needed for hotter or more humid conditions.

Base layers

What you wear next to the skin is of paramount importance. How comfortable you feel, and how efficiently the layers worn on top work all comes down to wearing the right base layer. In short, the kiss of death is anything made of 100 per cent cotton. The problem with cotton is that it absorbs moisture and it takes forever to dry out. More preferable is the 'wicking effect', where moisture passes through the base-layer fabric so the skin stays as dry as possible, rather like a high-tech nappy. This effect is important in cold conditions, where you have layers on top, because keeping the moisture moving away from you will prevent the chills when you stop moving. And it is particularly important if your outer shell is a breathable waterproof because if cotton is worn next to the skin, you might just as well wear a bin liner rather than a £200 or £300 Gore-Tex jacket.

In warmer conditions, where the base layer may be all you are wearing on top, it helps keep you cool by wicking the moisture to the surface of the garment where it can evaporate most readily and therefore cool one down. Helly Hansen started the ball rolling years ago with polypropylene base layers, but technology has moved on considerably since then. Polyprop tends to get smelly very quickly, while the latest polyester fabrics, epitomised by Polartec's BiPolar, have anti- microbial treatments that will keep them working and smelling sweet, even under the most arduous laundry-free conditions.

Mid layers

The traditional garment here is the woolly sweater, and devotees say that not only does wool absorb moisture, but it even generates a certain amount of heat when it does so. But once again, if you are wearing a high-tech breathable waterproof on top, it is not allowed it to do its job by encouraging moisture to hang about inside your little microclimate. The modern alternative is fleece, made from knitted polyester, napped and sheared in a wide variety of different velour finishes, depending on the performance and look required by the manufacturer. As with the polyester used in base layers, it absorbs a mere one per cent of its own weight in water, and the sophisticated techniques used in its construction ensure excellent insulation for the weight of the fabric. Fleece comes in different weights, and the most widely available weight - the best for a broad range of temperatures - is the 200 g/sqm fabric typified by Polartec 200. The heavier weights are better for very cold conditions or inactivity in less extreme temperatures, while the lighter ones are useful for warding off the chills of a summer evening, or as an extra 'thermal' layer.

On its own, fleece is not windproof. In many situations with high activity - cross-country skiing, for example - a certain amount of air permeability can be an advantage. If windproofing is needed then you can either wear your waterproof on top, or a lightweight windproof layer made from poly/cotton or synthetic microfibre. Windproof fleeces made with a laminate sandwiched by two thin layers of fleece fabric are available, and while they do an excellent job, it is unfortunately at the expense of flexibility in an overall layered clothing system.

The legs

Cotton canvas jeans have been around for over 100 years, but while they are robust, they have little else to offer. Unless you buy the stretch variety, jeans are unyielding and take forever to dry when washed. In my opinion, they make appalling travel clothing. Get them wet in cold, windy conditions and they become downright dangerous. Water conducts heat away from the body 26 times as efficiently as air, so cotton trousers that absorb gallons of the stuff are not good news for the legs unless you are a fan of hypothermia.

Polyester/cotton or polyester microfibre fabrics fare much better in unexpected extremes of climate because they dry off much quicker. Besides, most travel trousers made from these kinds of fabric look smarter, too. For trekking and mountain walking, the best performer without a doubt is Polartec Powerstretch fleece, but given that a pair of leggings made from Powerstretch will be 'form-fitting', do bear in mind any social considerations when wearing them away from the mountains.

Waterproofs

The buzzword these days is 'breathability'. Most will have heard of Gore-Tex, the best-known microporous laminate, but there are also microporous polyurethane coatings, and there are, in addition, coatings and laminates that are hydrophilic - Sympatex, for example, the biggest-selling breathable waterproof laminate in Europe. They work by different mechanisms, but the effect is the same. Moisture vapour on the inside gets transmitted through the membrane or coating to the outside. They work best when there is the greatest difference in both temperature and humidity between the microclimate inside your clothing, and the air outside. In other words, cold and dry conditions will see the best performance.

While there are differences in performance between fabrics, and even different versions of the same fabric, what is probably more useful is to concentrate on the design of the jacket. If the most robust waterproof is needed, you should aim for one of the laminated fabrics in a three-layer configuration. They are good performers, but not necessarily the best for looks if you are seeking something a little more general purpose. Here the two-layer laminate with a separate lining comes into its own, in fact all but budget jackets made from polyurethane-coated nylon or polyester will come with a drop lining as well. The advantage is that they feel softer and look smarter and more sophisticated.

The main zip needs protection to stop water getting through. This should be a double storm flap - either Velcro or press stud fastened - with the inner flap slightly oversized to form a gutter so that any drips managing to infiltrate that far can run down to the bottom hem.

A good hood is essential. A walking jacket may have a fixed hood, but more are now coming with rollaway hoods that stow in the collar - simply because people want the jackets to be multifunctional. The drawcord adjuster should bring the hood snug around your face without too much fabric bunching up, and it should allow you to turn your head from side to side without your face suddenly disappearing inside the hood. Something that started out as a feature on mountaineering jackets but is becoming widely available on general models is the volume adjuster. Usually an elasticated drawcord or webbing strap and buckle at the back of the hood, it allows you to take up excess volume in the hood, giving a better fit.

Also useful is a decent peak or visor to keep drips from running down your face. Visors made for typical hillwalking or mountaineering will tend to come with some form of stiffening - either a thin plastic strip or malleable wire. In recent years, however, the trend has been towards soft visors, which make stowing the hood in the collar easier, but it is at the expense of functionality when it really counts. In high winds, a floppy peak will simply collapse over your eyes. Old- fashioned designs do give a rather closed-in feel - the more up- to-date ones have cutaways at the side of the face so no peripheral vision is lost - important when you are picking your way across uncertain terrain.

If you really want to batten down the hatches in bad weather, look for elasticated drawcords at both waist and bottom hem as well as the hood, while cuffs need to have a good range of adjustment to allow for sealing around gloves.

Pockets are really down to one's own preference and needs. Certainly if you are navigating yourself through wild terrain, a map pocket in the proper place can save you some grief. Decent map pockets will be situated at chest height with the zipped opening beneath the main zip storm flaps, but outside the main zip itself, affording access to your map without opening up the main body of the jacket.

Insulated clothing

If you are heading for really cold climes, or maybe you just need something warm to wear around camp if the temperature plunges to freezing or below, you might consider an insulated jacket, something filled either with polyester wadding or down. As with sleeping bags, the two forms of insulation have their pluses and minuses. Duck or goose down provides the best insulation for the weight - it is also more compressible, and it regains its loft better after compression. The big minus is that it loses its insulation value if it gets damp. Even an insulated jacket with a breathable waterproof shell can suffer from a build-up of moisture that will affect its performance. The first line of attack is to make sure it doesn't get wet. You can also impregnate the whole garment with a waterproofing agent, which will enable the down to loft even in damp conditions.

Synthetic waddings tend to be cheaper than natural fillings and, in general, are bulkier and have a shorter lifespan, though with the huge advances being made in the technology over the last few years, this is not always the case. Their big winning point is the fact that damp does not affect their performance.

Intelligent clothing?

It is now possible to make garments from fabrics incorporating phase change technology, promising superior temperature regulation. The idea is that if, say, you were exerting yourself while wearing a jacket made of the material, it would prevent you from overheating by changing phase and absorbing the excess heat. Then, once you stopped moving and began to cool down, the phase change material would revert to its former state, releasing heat in the process. The technology itself is brilliant - the drawback is that in order to get it working really well, you would end up with garments that were prohibitively expensive. The garments that are currently on the market have such a small percentage of phase change material in their construction that the benefits are negligible.

Head and hands

The head radiates more heat per square centimetre of skin than any other part of the body (up to 70 per cent of the total heat loss from the body). The moment you start feeling cold it is advisable to put a hat on. A woolly hat is fine, although if you find wool next to the skin a bit irritating, there is a huge range of styles made from polyester fleece.For maintaining any dexterity, in order to operate a camera, for example, you are better off using thin liner gloves with heavier gloves or mittens on top.

Sun protection

The rate of increase in new cases of skin cancer is alarming, and the age of onset is getting lower. We now know there is no such thing as a healthy tan, but also that we can improve our protection against the sun by wearing the right kind of clothes. Most people are unaware that while parts of the body covered by light clothing do not get tanned or burned in strong sunshine, the skin is still being damaged. UVA rays cause tanning and burning but UVB rays go deeper, causing more long-term damage, and they can penetrate many types of light clothing. The average cotton T-shirt has a SPF (sun protection factor) of between six and nine. That drops to less than half if the T-shirt is wet.

We tend to regard lighter colours as more suitable in bright conditions because they reflect better. In fact the opposite is true. Darker colours absorb more UV and therefore provide better skin protection. The best fabrics for sun protection can still be lightweight, but are close-weave. Some travel clothing companies - Rohan and Craghoppers in particular - now quote SPF ratings for their products.

As with base layers, synthetic or synthetic/natural fabrics are best. First of all, synthetic fibres can be made finer than cotton, and are therefore capable of being closer woven. Secondly, their quick-drying ability means enhanced cooling in conditions where you are likely to be sweating. A hat makes good sense, too. The head and neck are prime targets, with one-third of all skin cancers occurring on the nose. A mesh-topped baseball hat or open-weave straw hat might feel good, but they do not offer sufficient protection. A hat with a ten cm all-round brim is much more effective.

Footwear

What one wears on the feet can make or break any trip. So whether your preferred footwear is trainers, loafers, deck shoes, brogues, walking boots, sandals or wellies, you can do yourself a big favour by making sure they fit properly, and not leaving it until just before you head off into the blue yonder to buy a new pair.

Boots

Walking boots used to be heavy, unbending lumps of leather that were designed to inflict major injuries on feet until they had stomped at least 100 miles in them. Nowadays, while boots may need a little period of 'acclimatisation', they are designed to fit and to be comfortable, straight out of the box. For non-demanding walking and trekking, lightweight boots, such as the mega-selling Brasher Boot, will be just the job, and they don't look too bad for wandering around markets.

The main choice is between all-leather and fabric/leather boots, and within those distinctions there are models built to cater for very wide levels of usage, from general ambling on undemanding terrain to four-season mountaineering. Much of it comes down to the stiffness of the sole unit, but even a boot designed for footpath walking - with a reasonable amount of flex in the sole - should still not be able to twist too much. If it does, it will offer little support on rougher terrain, and the feet are likely to tire more quickly.

The key to ensuring a decent fit lies in making sure you have the socks you intend to wear with you when you are shopping for boots. Remember that you should leave space in front of your toes to allow for feet expansion, and the easiest way to do that is to slide your foot forward as far as it will go in the unlaced boot. You should then be able to slip your index finger into the space between the heel and the back of the boot. If you can move the finger about, the next size down is needed, if it is very tight - then the next size up. Any outdoors shop worth its salt will have the means to measure feet accurately.

Insoles

Since it is likely you will spend lots of time on your feet, it can be worth investing in a pair of specialised insoles to provide superior support. Those that are provided as standard in many walking boots and trainers are generally made from soft closed- cell foam. They help cushion the feet and prevent blisters, but aren't as supportive as they could be. Probably the best insoles you can get for boots, shoes or trainers are those made by the American company Superfeet. By providing better support for the feet, they prevent the elongation that occurs when you put weight on them, which in turn prevents a wide range of long- term problems.

Sandals

When the first sandals that took over from flip-flops came into being (mainly for rafting in the US), they were fairly basic - nothing more than a sole with Velcro-fastened nylon webbing straps. Now sports sandals are extremely sophisticated, employing all the technologies used in high-tech footwear to provide comfort and support. The soles are generally supportive, many with good gripping outsoles, with shaped footbeds to add to the feeling of support and comfort. The straps may be made from nylon webbing, leather or synthetic leather, and most will have soft padding or linings on the underside.

There are versions made for use where immersion in water is likely, but equally there are versions that are suitable for hard walking. Indeed, there are many hikers in the States who prefer to use sandals in hot conditions, even when backpacking heavy loads. Since it is likely that you will be wearing sandals in hot, sunny conditions, do be mindful of the fact that the skin on your feet is very sensitive, so either use sunblock or wear a pair of socks.

Happy feet

Decent socks are as much a key to foot comfort as the shoe or boot itself. Look for socks without bulky protruding seams over the toe or round the heel, and check that the elastication at the top is not too tight. For walking and general travelling, loopstitch socks provide greater cushioning underneath the heel and ball of the foot, and you do not have to burden feet with the extra insulation of a full loopstitch sock - socks with the loop pile just in the strategic areas are now available.

Remember that the layer principle gives the greatest means to mix 'n' match, both in terms of performance and looks. The good backpacker keeps his load light by using items of clothing and equipment, which, where possible, serve more than one purpose. So as one begins to select clothing to put into that rucksack, travel bag or suitcase, think versatility and don't take more than you really need.