I face away from the tree unless it's been a really slow day and I need a change of scenery.

I like to keep my best shot alleys in front of me or to my left with a few decent sized trees between me and the main trail.
That way I can draw without being seen when the deer's head goes behind a tree trunk. If a deer walks by on the trail from in front of me to my left, then I will get a broadside shot at my left. If the deer walks along the trail from my left to in front of me, then I'll have a quartering away shot when he gets out front. I learned my lesson the hard way about this. My first deer was almost a non-lethal wounding. He was on my off-side (right for me), and I was too close to the trail. He was too close to risk changing my foot position and I took the shot with my feet facing forward and my bow pointing to my right at about 2:00. It was tough, and I messed up the release a bit causing my arrow to hit the spine and ground him. A finishing shot was easy enough and he died quickly, but I felt badly enough that I'll never take that shot again.

I also stay in the shade or have the sun at my back whenever possible.

I try to keep my back to dense cover so I don't get blindsided. That way if a deer comes past, he has to do it in front of me.