If you know you're going to be in a particular city between certain dates, book a hotel or hostel bed in advance. The same goes for popular attractions that you know you're going to want to visit. It's not a lot of fun turning up to find they don't have space for you. Alcatraz in San Francisco is one such attraction.
A huge number of hotel and flight bookings are made through websites these days, but if you do make a booking over the phone, ask the customer service agent to read your details back to you, and be especially careful that they have taken your credit card and contact details correctly. If you are booking over the internet, double check that you've typed in all information correctly. I turned up in Seattle only to find that my reservation had been cancelled because the guy on the service desk wrote down my credit card number incorrectly.
Know where you're going.
Every country has its own unique set of laws. Find out whether you're required to carry photo ID at all times, or if a country's authorities recommend you only carry a photocopy. Try to find out what tricks and scams are common in the areas you're visiting, and how to avoid them. An easy way to get clued up quickly is to travel with a guide book. I've always found the Lonely Planet range very good, but the Rough Guide is pretty handy too. And if you're going to be driving, make sure you know how road laws are different in each country you visit.
Get travel vaccinations in advance.
If you're travelling to foreign countries, you need to check whether you'll be visiting areas that pose a health risk. Many travel vaccinations must be administered several weeks before you travel, so don't put this off until the last minute. My local practice nurse tells me that certain countries require a certificate declaring that you've been correctly vaccinated for yellow fever, and if you fail to show such a certificate you'll be forcibly vaccinated, stuck in quarantine for a fortnight, and then sent home. Don't make guesses about what protection you need.
Buy travel insurance for foreign travel.
If you are travelling to a foreign country, make sure you buy travel insurance. Some types of insurance you can do without, but travel insurance isn't one of them. If you're an EU citizen, you should get yourself a European Health Insurance Card. This will cover the cost of emergency treatment in most EU countries, but there are still many costs that the EHIC will not cover, so you still ought to buy travel insurance.
Declare everything on insurance forms.
If you're buying travel insurance, the insurance company will require you to declare any existing medical conditions, or any reasons that may force you to make a claim on a travel insurance policy. Declare everything and don't assume that a medical condition or minor operation will be of no interest to the insurance company. Even close relatives with serious illnesses will increase the premium you pay. If you have to make a claim, and the insurance company decides that you witheld information from them, they may refuse to honor the claim. If in doubt, ring the insurance company and ask them.
Bring clothing that covers a range of climates.
It's easy to think that travelling to a hot country means that you only need lightweight clothing, but you never know when you're going to be subjected to cold or wet conditions. A friend and I nearly froze because of powerful air conditioning on a night-time coach journey to Douz. All we could do was shiver while wishing we'd each stuck a pullover into our carry-on luggage.
Buy good quality gear, especially footwear.
On an eight-day trip to Tunisia, I was wearing a pair of cheap boots that I'd bought for the trip. My feet were in agony by the time I reached Tunis. Don't buy cheap clothing when you'll need to rely on it for days or weeks at a time. Find recommended, durable, comfortable clothing that has personal security in mind. For example, look for trouser pockets with a zip or hook-and-loop strips to deter pickpockets. This advice applies equally to bags and backpacks.
Buy a good suncream lotion.
Even in winter it's possible to be confronted with a sunny day that doesn't let up. I got sunburnt in Galway in winter because I'd assumed that suncream was unnecessary. If you're going to be spending time outdoors, make sure to buy a good suncream and make sure you understand how to apply the stuff properly. Most suncream lotions need to be applied twenty minutes before you expose your skin to the sun, otherwise they don't work.
Buy a travel first aid kit.
Whether you buy a pre-packed kit, or make your own, a small supply of sticky plasters, gauze and mild painkillers may be a useful thing to have with you on exotic travels. (Check before you take any drugs into another country, even if they are legal at home.) Luckily I've never needed to use such a kit while travelling, but if you're in a town on the edge of the desert, or on a small island without its own medical facility, it's good to at least have sterile wound coverings.
Think about home arrangements.
Do you need to suspend milk delivery? What about magazine subscriptions? Newspapers? Having stuff pile up behind your front door lets people know that no one is home, which may attract burglars. Ask a friend or neighbour you trust to drop in and move the letters, magazines, and junk mail out of sight. If you have a pet, remember to ask that trusty neighbour to feed it while you're away.
Put film into your camera.
If you're one of the people who still use a film-based camera, make sure that the excitement of travel doesn't make you forget to load film into your camera. Going sightseeing to the same place twice may test the patience of your fellow travellers. My friend forgot to put film in his SLR camera while in Prague, and only noticed on the third day we were there. So it was back to Prague Castle for a lightning second tour, so that his photo collection didn't suffer.
Don't let your guard down.
Romantic notions of foreign travel will get you into trouble. Letting my guard down led to me losing fifteen quid to a trickster in Sousse. Don't think you can trust strangers just because you're abroad. And don't lose your sense of judgement just because you're excited to be somewhere new. Some people go nuts and buy a house on a whim just because they're enjoying themselves so much. If you wouldn't do it back at home, then don't suddenly think it's a good idea on holiday.
Don't mess about in remote places.
If you take a wrong turn in the desert, or on a mountain trail, you may never be seen again. Don't travel to these places alone, don't go there without taking local advice, and try to let someone know where you'll be going. Telling your hotelier is probably a good idea, because at least they'll notice if you don't come back to your room at the end of the day.
Don't throw yourself at the language barrier.
Stick to bars and restaurants that display, by the door, a menu in a language you understand. Going into a restaurant with waiters that can't understand you will probably result in each member of your group getting something unexpected. In a nice restaurant in Prague, my request for a Coke resulted in a half-litre of beer being brought to me, and my friend's request for a bit of pork resulted in a gargantuan leg of pig being delivered.
Make sure you either change the time on your watches, travel clocks, mobile phones, laptops, etc, or know how to set and use the "travel mode" offered by some of these devices. We nearly missed the Gothenburg to Oslo train because my friend, a travel veteran, brilliantly managed to set an alarm on his mobile phone without realising that the thing was still showing UK time, one hour behind Swedish time. He only woke by pure chance, twenty-five minutes later than planned, and we had to rush like crazies, catching the train with less than ninety seconds to spare.
Keep an eye on your bank balance.
If you're going to be doing a lot of travelling, take your bank's phone number with you and ring them every week to check your balance. It's very easy to lose track of how much money you're getting through each day. Also, budget necessary future expenses into how much money you have left. In New York, on my last day in the USA, I went to an ATM to get some money to buy souvenirs with. Computer said no. Funds unavailable. Luckily I'd already paid for my hotel room and bought a Metrocard, otherwise I'd have had no way to get to the airport for my flight home.
Don't be a tit.
After rain had fallen in the streets of Prague, I attempted to do a running slide across the slick-wet cobble stones. I fell on my ass.