1. iPod - obvious suggestion, but you've got to add stuff that will help you relax or even sleep. My personal choice is Boards Of Canada, The Orb and several soundtracks.
2. Melatonin - it works. Available over-the-counter here. Not so for my German friends.
3. Noise-canceling headphones. And you don't have to spend a lot of money. My 50 USD Sony MDRNC7 works almost as well as the 100 USD ones I borrowed.
4. Don't let hotel housekeeping clean your room. You don't need clean towels every day (also good for the environment) and it actually takes more time and effort to put everything back where you want it. Plus you don't have to hide valuables.
5. Buy shampoo, conditioner, soap and kleenex locally. It's not that expensive, reduces packing time and luggage weight and still allows you to use most of your favorite brands.
6. Buy a liter of water before checking in at the hotel. For some reason, I don't drink as much when traveling and end up dehydrated.
7. Bring a sweater or pull-over, even if your departure and destination locations are warm. Some planes are cold, some are hot, but this gives you options.
8. Mint gum. For those times when you can't brush your teeth. Plus everyone wants a piece.
9. Take your shoes off on flights. But try to bring an extra pair of socks.
10. Eat big breakfasts and dinners, but light lunches. Work longer and sleep easier.
So what did I miss?