We returned to our campground outside Orlando to find several gleaming, giant customised Harley Davidsons parked in the space next to ours. "Get off!" I bawled to my kids, who were clambering onto them, "or the owners will be really angry." The owners were angry. A group of greasy, dangerous-looking Hell's Angels approached, menace in their eyes. "Why have you got tattoos?" asked Charlie, four.

But that incident illustrates one benefit of travelling with kids: they are fantastic ice- breakers.

They also lend a fresh pair of eyes. A couple of days later we were at Seaworld, waiting for the Shamu, The Killer Whale show to start. Suddenly a 40-ton, aquatic mammal shot out of the massive swimming pool. "That's not a penguin, is it?" three-year-old Nicolai confirmed.

Moving on to Memphis we toured Elvis Presley's house. We spent four hours in Graceland, learning about the king. 'Maybe this trip is educational, after all,' I thought.

But two hours later, on Beale Street, downtown, we spotted a life-sized Presley poster. "So boys," I said. "Who is that man?"

Our American journey (three months in a motorhome, two kids, no wife) was the most ambitious trip I've ever made. My wife, Khelga, was busy with work exams, so I proposed the idea of a drive across the States. I would fulfil a Kerouac dream. The boys and I would have a father-and-sons' adventure. She would have calm space in which to study.

Khelga took a while to buy the idea, but as soon as she was persuaded I remortgaged the house. For three months I had zero income, substantial expenses and 24 hours a day with two pre-school kids.

But that was a benefit. How many children and parents (especially dads) spend 24 hours a day together outside the annual summer holiday? The boys and I got to know each other extremely well and shared a unique experience.

Driving through the southern states in a motorhome in summer, stopping off at beautiful parks and campgrounds, they had space, sunshine and freedom.

North America is one of the easiest countries to travel in with children, but the boys and I have ventured into other places too: Egypt, Israel, Iceland, Kenya, Europe, the Caribbean, Russia. We've driven, we've flown, we've taken trains and ferries, we've cycled, we've even hitchhiked together.

To progress from being a traveller to being a globetrotting parent is a fear-inducing, lifestyle-jolting, jump. But even the most jaded palate will find new sensations in a world suddenly filled with little people. There's no set formula for travelling with children and, as with any trip, there is always a risk. To help things go smoothly here are some tips I've acquired from my experiences, both good and bad.

When to start

"Do as much as possible while he's still being breastfed," friends advised when Charlie arrived. "You're much more self-sufficient and don't need so much junk." (I did need the wife though, which wasn't a problem).

The first trip was two weeks in Puerto Rico, followed by a winter stay in Canada. Charlie was two months old.

First disaster was the loss of our luggage when we flew to Montreal from San Juan. It had been plus 30C when we took off. It was 30° below in Montreal. "Not to worry," I said cheerily, as we walked to our car in a blizzard, snow and ice strafing our arms and legs. My wife and I were dressed in shorts and T-shirts, Charlie was swathed in borrowed airline blankets.

Lesson one in travelling with children: always keep a spare supply of clothes as hand luggage. You never know when you might need them. And as for travelling while the baby's still breastfeeding - nothing can be taken for granted. The following week my wife's milk dried up.

As kids reach toddler stage they sleep less, and demand more attention and equipment. (It's only when you can chuck the buggy away that you finally begin to feel liberated.) Kids aren't really going to appreciate their travels until they begin to communicate. Of all the animals on safari in Kenya, two-year-old Nicolai loved the local sparrows best.

Preparation

Make sure that you've had all the required injections well in advance of your departure date.

Prepare lists of everything you need. As well as practical stuff, don't forget favourite teddies, toys or books. But don't go mad. Limit what you take - travellers accumulate stuff. And if you're going to North America, take very little (and buy over there - nearly everything is cheaper than it is in Europe). In hot and cold climates, remember that hats are extremely important.

As children get older, prepare them psychologically for travelling. If you're having an adventure (rather than a holiday) they should be aware that life will be different.

Flights

Flying with children isn't always a nightmare. Letting the kids go to bed late the night before is a high-risk strategy but it can work. My boys were so excited the night before one long-haul trip that they didn't settle until midnight. Such was their exhaustion, they fell asleep shortly after take-off and I spent most of the flight undisturbed. But you can't rely on that. You often have to think on your feet. One tip here: sick bags fascinate all children and, with some decoration, make good glove puppets, too.

Airlines vary in their attitude to kids. Virgin Atlantic are deservedly famous in that department. They give out lots of goodies and staff are very tolerant. But some charter airlines can be hell - even exhausted children can have problems sleeping in cattle truck conditions. If you're making a long-haul flight consider the advantages of scheduled over charter.

Manage expectations. If you're flying to South-East Asia and your children want to know if you've arrived just as you pass over Hounslow Heath, be honest... Tell them they are going to be on the plane a very long time.

Flying dehydrates, so keep children watered.

Food

No matter how well airlines cater for children their idea of a child-friendly meal is usually revolting fast-food junk. Sugar and additives aren't the most child-calming ingredients for a flight. So don't feel obliged to order a kids' meal. As a precaution, pack your own in-flight snacks - with whatever healthy things your children like.

When it comes to food, I must confess to being totalitarian with my boys. So they're used to a varied diet and generally eat everything on their plate. This has been useful on our travels as they're happy trying out new things. Prepare children for a different diet by producing new dishes at home before travelling (and warn them that they won't be able to have burgers or chicken nuggets for every meal.) If your kids are fussy eaters, stock up on supplies they'll probably like - dried mince or noodles usually go down well. And use different tricks to lure them into trying new things: e.g. Superman eats tom yum when he's in Thailand; Mickey Mouse eats pork fat when he's in Costa Rica; Batman eats turtle blubber when he visits the San Blas Islands.

On the road

The most important requirement when travelling with children is flexibility. It's all very well making itineraries, but one tired toddler ruins everything. Never push kids. Go with the flow. If they seem tired, err on the side of caution.

Be prepared to do or see half the things you want to do or see. Be prepared for days of doing nothing - catching up on sleep (you and the kids); lounging by a pool, chilling out...

If you've crossed a time zone, give the children time to adapt. On the third day of our American trip I was woken at four in the morning by two naked boys cycling inside the motorhome.

Compromise. If you're a culture vulture don't expect your children always to share your interest. If you have to visit a museum, check whether it has a children's section. If it doesn't, take into account the kids' tolerance threshold and reward them for their patience with a treat - a visit to a waterpark, swimming pool or zoo, anything they're bound to enjoy.

Don't lose the children. But if you do (and you probably will) make sure they have some information - their own name, your name, where you're from. I had a frightening experience when Nicolai vanished on a campground outside Nashville. After 15 minutes he was delivered by a fellow camper. "Sir," said the man. "Are you Mr Collins?"

Illness

If you're away for more than a fortnight, it's likely your child will be ill. First tip: make sure you have good insurance. Second tip: choose the contents of your medical bag carefully - preferably in consultation with your family doctor (and keep it with you at all times). Third tip: (again) don't push your children. If they get overtired they're more likely to get ill.

Our worst experience was when Nicolai suffered febrile convulsions on a ferry from Santander to Plymouth. We had to watch helplessly while a nervous French doctor calculated the appropriate dose of sedative. Oh, the guilt... we'd travelled all the way from Seville that day.

Take the usual culinary precautions - peel fruit and veg, avoid buffet food (which has been left standing out), and avoid ice in drinks. Watch your child's fluid intake. Children dehydrate more quickly than adults. If they develop a fever or any illness involving diarrhoea or vomiting, get them to take water mixed with sugar and a little salt. The juice of an orange makes it palatable. Pack camomile tea. You can use it for everything from upset tummies (drink it) to heat rash (apply it).

If your child develops a temperature over 39C, find a doctor, fast.

Final tip

Warn your child when he or she goes back to school that, just because he/she has spent the summer trekking up the Himalayas or sailing down the Amazon, he/she mustn't expect every other child in the class to have done the same. After my Charlie had recounted his tales of bear spotting, trout fishing and glacier crossing in Canada, his friend William informed the class he'd spent the summer in Clacton with his granny. But at least William was more interested in Charlie than a boy called Thomas, who hadn't been away at all. "Oh, be quiet," he said. "We're not interested in Charlie's boring travel stories."