Other than the obvious need to get into the best shape of which you are capable the best thing you can do is to arrive at elevation a few days before your hunt to scout and get your body acclimated.

Wear good boots, forget the calls, and plan to hunt the rough country that most others avoid. By second rifle season elk in OTC units get spooky from being pushed around by hunting pressure. Go up early (before light) and come down late (after dark), take a nap on the mountain in the middle of the day, and do not plan on seeing your camp in the daylight.