We have USH annual passes. The rides have staggered starting times, so be sure to get the day's schedule as you enter. Also, USH has two areas: the "Upper Lot" and the "Lower Lot," which opens later. The two lots are connected by a series of slow escalators, so you want to visit the Lower Lot once.
If I had out of town guests who wanted to do as much as possible in one day, I would first go on the Studio Tour (it's one of the first things to open), then go to the Lower Lot (Revenge of the Mummy, Jurassic Park, and anything else of interest). Then back to the Upper Lot for other rides and shows.
Woody