Congrats on the tag. Best advice: read through any thread in the Mule Deer section with more than a couple of pages of posts, going back several years. It's an absolute gold mine.
Couple of key points:
1) Don't worry about hunting water - they'll go days without watering, and will often be miles from the nearest spring. Focus finding the herds in places they feel secure, close to their food. They need that daily.
2) About the only gear purchase you can make that will give you a genuine advantage are really good binos that you can spend hours glassing with. The higher the quality, the longer you can stay in the glass without getting eye-fatigue.
3) Hunt the shade. That's where they'll be from just after sunup to just before sundown. Do not go back to camp mid-day - keep hunting with your optics, all day. You'll have a chance to see them move from first-bed to second-bed around 10am, give or take an hour on either side. You'll also see them stand up for 1-5 minutes at the height of the sun to move a few feet as the shade moves from the sun's transit.
4) Never skyline yourself - it's a beacon to mule deer, even for a microsecond. Duck down below the brush line, crawl if you have to, and set up your glassing spot so there's no way you can be silhouetted against the sky.
5) Glass 5x more in one spot than you think you should - looking for tiny flickers of movement and deer parts. Tines, ears, hooves, tails, etc. When you think you've overglassed a spot...move 15 feet and do it again. Just that little shift can get you big differences in perspective and visibility.
6) Never give up a sunrise - be in-place well before sun up. Same with sunsets. Stay until you have no visible light. If nothing else, you'll have a lead for the next day.
7) The sun is brutal here - high elevation, clear skies, dry air. I don't leave my truck without at least half a gallon of water on me, and that's for short trips. Day hiking for scouting it's a gallon across a couple of different containers, sometimes more if I've got a hard hike ahead to get to a particular spot. Bring sun screen, lip balm, and long-sleeve clothing that can also cover your neck in one way or another.