To help with altitude, start taking a baby aspirin about 6 days before you come. It will thin your blood a bit, altitude makes it thicker. Try to eat more garlic the week or two before and put lemon inyour water, both are natural blood pressure droppers. Thick blood and higher blood pressure at altitude is really what makes you miserable. Blood can't absorb enough o2 and combine that with less o2.... Blood pressure naturally raises for the first 2-4 weeks at altitude because of the decreased pressure on your vessels as well as increased fluid in them from expansion..
Another think to do is avoid excess carbonated drinks and excessive carbs cause they expand twice as much and can give you intestinal and stomach cramps from gas!