Now that you've signed up for the trip, spent a couple of months getting into shape and make sure your gear is appropriate.
Begin your trip in good health - if you become sick immediately before the trip, let your leaders know ASAP.
Protect yourself from the sun - a brimmed hat, sunscreen, lip balm, sunglasses are a must on all of the trips.
If your trip is at altitude (above 8000-ft), try to arrive in the area a few days early to acclimate. This isn't always possible, but if you've had problems at altitude previously it is a must.
Drink a lot of water - more than you feel you need. Most participants live near sea level, and the amount of water loss as you gain altitude in the arid parts of our country is more than you would expect. Often folks stop drinking in the evening so they don't have to get up in the night, but we encourage you to drink throughout the day. If you get up at night, you'll have an excellent opportunity to see the stars.
While drinking water is vitally important, you don't want to drink out of other folk's water containers. Folks come to the trips from all over the country, and we all have different germs living in our mouths. Bring enough water containers to carry all the water that you need during the day (a minimum of three one-quart containers, four on desert trips).
If you become dehydrated, you must slow down and get rehydrated. One of the first signs of dehydation is a headache.
Eating is also important. Eating a varied diet is the best way to keep your water/salt balance intact. Eating small snacks during the day is often better than one large lunch.
Take good care of your feet. Tape areas that you know are prone to blisters. Treat hot spots immediately. Let your feet breathe out of your boots during lunch breaks.
Hand washing is one of the most important things you can do to stay healthy. Your trip leaders will have a hand washing station set up for you to use -- use it frequently!
If you feel badly during the trip, be sure to let your leaders know early. Little problems can become big and should be watched. The same thing goes if you hurt yourself; little scratches can become infected.
While most folks think that hiking uphill is the hardest thing to do, hiking downhill is actually harder on your body. Fighting gravity with your thigh muscles is hard work, and your feet tend to slide down in your boots and rub your toes. The best way to prepare for this is to be in good shape before the trip.
Cut your toenails as short as possible (this will keep you from losing toenails!).
During the trip, lace your boots properly. You'll notice that there are two types of eyelets on a good pair of hiking boots. The ones along the top of the foot are usually closed metal rings, and the ones going up from the inside of the ankle are the quick-release type. What you'll want to do is lace your shoes with some give through the lower eyelets-not snug but not real loose either. Then do a single very snug overhand loop with the laces just before you start lacing through the quick release eyelets. Lace through the first pair of quick release eyelets and then do another snug overhand loop. Lace through the next pair, and again, do another loop. Do this all the way to the top of the eyelets. Once you've tied your bootlaces, I recommend taking the two loops and tying them together - just like you do kid's shoes.