This isn't preaching, just advice...try target shooting from the treestand. If you plan on using one, you should include this into the practice sessions at least a few times in the preseason. You should try to do it now, if possible. In a pinch, I go up on the roof and shoot. All the other advice above is good and feasible, but the one that is most likely the problem is not bending at the waist. When shooting from a treestand, shots will always be higher, unless you use proper form and bend at the waist and not with your arm (which many people do, use there arm). Bending at the waist means drawing and holding as if you were standing on the ground, then, without moving the bow or any anchor points, bend at the waist. The bending at the waist, proper form scenario needs to be practiced as well. It may not be natural when in the treestand.

Also because it was mentioned above... with shot placement, try drawing an H just behind the front leg on a broadside deer, then put the arrow just below the middle line that connects the two (in the center of that line. It may not be easy to visualize the H at the moment of truth, but if you do and it hits just below the middle line in the center, it has a very high chance (probably will, but you never know) of being a double lung.


Only my $.02
Brian