My ideal spot is near water and less than an hour hike from my first light glassing area. I generally want to be downwind from where I expect animals to be, and try to use the topography to shield my noise so that I'm not tiptoeing through camp the whole time trying to be quiet. especially when I'm solo though, I may end up sleeping at my glassing spot, tanking up water and sleeping way up high, etc. I don't really have any hard rules, other than I avoid being right in the middle of animals.
This last season, we set up on a bench on a steep hillside a few hundred feet above a creek in some thick timber. That spot was ideal, and we were able to hike in just about any direction and glass. Dumb luck, we ended up glassing a group that we harvested a cow from right from our campfire. We also had bulls bugling right on the other side of our camp while we were talking and laughing. They were even bugling at us when we were calling each other. They sounded like they were gonna walk right in to our camp and fight us haha.