To me the most important thing to remember is that I need to mentally "visualize" the arrow's path through the deer in 3-D, and aim to put the arrow through the vital organs (lungs or heart) I want to hit.
The aiming point for a ground level broadside shot at 15 yards is much different than the aiming point for a quartering away shot at 5 yards from 15 feet elevation in a stand! - Aim at the ground level broadside "target" on the deer's side for the elevated 5 yard quartering shot and chances are you will only clip one lung!
I don't worry too much about the arrows trajectory making it hit high/low due to the elevation. It will make a slight change in POI, but not enough to loose a deer if I was aiming at the correct spot.
I might add, I use only one aiming point in my scope (the crosshair) when deer hunting. I sight in dead-on at 25 yards with my Phoenix and use the crosshair for any deer from 0-30 yards. Close shots will hit a couple inches (at the peak of the flight trajectory about 2½" high) up close and a couple inches low at 30 yards, but if I held "center of the lungs" and made a good shot it is a quickly deceased deer!