Sun at my back, I like to be able to glass from 3- 5 miles in multiple directions. Don't want my glassing spot to only give me the ability to see one slot canyon. I like to find a spot that I can move several hundred yards and getting different angles and vantage points and don't have to skyline myself.
Another important factor with wind is to have some protection from it, tripods and optics plus heavy winds are not a good combo. I typically have some habitat that I would like to be able to look into (like shaded areas where deer bed) and make sure the glassing point will be good for it.