When shooting from a stand say, 15 feet up. How low should you hold on a deer around20-30 yards away?

Aim for the vitals...I dont compensate for nothing! If your bow is dead on you should not have a problem unless it is shooting at 5 feet per second. Now I have "heard" guys say the deer will duck but in my case I have never seen a deer duck any of my shots. Trust your equipment and your shot placement. BOTTOM LINE!

seems like if they hear you, their body will drop a couple inches as they turn around to start running away.

Well put "mahoningbuck" You hit the nail on the head!!

Hold at the top of the heart, pick a hair and give it to them......and read this: http://www.huntingnet.com/forum/tm.aspx?m=2297325&mpage=1