The single most important factor to understand when shooting from an elevated position, whether it's 12' or 120', is to bend at the waist and NOT drop your bow arm to get on target. Draw your bow just as you would if you were shooting on level ground, anchor, then without changing that T form, bend your waist to settle on target.

Like jm said, at those distances it won't matter as far as what distance to use, but don't drop your bow arm.......