--Ascending more slowly (e.g., stopping in Denver [elevation 5,280 feet] for a night to acclimatize).

--Refraining from significant exertion within 12 to 24 hours after arriving at high altitude.

--Improving physical fitness.

--Taking acetazolaminde prophylactically.

Note: It is controversial whether consumption of alcohol increases the frequency or severity of the symptoms.
{Ref: Hongiman B, Theis MK, Koziol-McLain J, et al. Acute Mountain Sickness in a General Tourist Population at Moderate Altitudes. Ann Intern Med 1993; 118:587-92.}