RE: How do you compensate for shooting from an elevated stand?
There's nothing else to know: Rick and Matt told you eveything; keep those two points in mind, and you'll be bringing meat home with every shot!
And be sure to practice from elevated positions, even if it means setting your treestand up prior to season just so you can.
Also, I carry an arrow with a field tip in my quiver (I've seen discussions saying some states don't allow that, so carry an extra field tip in your pocket or daypack) and pick out a leaf at 20 yards or so and shoot that before coming down at the end of each morning hunt for practice.