I'm lucky. I'm small, and I can sleep anywhere, at any time. This means I can cat-nap even in economy. I am prone to migraines though. I avoid those by being super careful about staying hydrated. I take multivitamins every day when I am on the road, carry protein bars in case I'm running late and have to skip a meal, and never ever pass up the chance for a drink even if I am not thirsty at the time.