1. Acclimatize and Exercise: I do a bit of exercise every day so my body gets used to the challenges of the elevation. Just light exercise. Don't go out and bench-press your weight, but walk around and stretch a bit. It shouldn't be too taxing, but it's important to keep moving so your body doesn't coagulate so much.
2. Watch Your Step: I'm a borderline fanatic about my feet. I wash them almost every other day on expeditions with soap and hot water, and then I wash them again with hand sanitizer to make sure all the germs between my toes are killed. I let them air-dry completely and then slather them with Burt's Bees moisturizer [$9; burtsbees.com]. I duct-tape blisters, and I wear one pair of socks, not two.
3. Tune In (and Out): Music has a time and a place. I've seen people listening to their iPods while walking through the Khumbu Icefall, and I tell them to take them off immediately. Mountaineering is dangerousyou need to be able to listen to your team and to the snow.
4. Keep It Clean: It's important to keep a clean environment when you're living in a tent for a month. One way to do that is to pack a small sponge to wipe water condensation off the floor. On winter expeditions, I shake the floor so ice breaks up, and then I scoop it outside with my hands.
5. Filter Carefully: I use the old standby Katadyn Pocket ceramic water filter [$240; katadyn.com]. It's virtually foolproof and incredibly strong. There's no bad aftertaste, either. Unlike SteriPENs and iodine pills, it takes the grit and gunk out of the water, and it's more environmentally sensitive than using fuel to boil it.