While "aim small, miss small" is certainly most of the problem, it's prolly not all of it. I would bet a dollar you are torquing the grip as well. Bow torque is the #1 killer of consistent shooting, followed VERY closely by bad arrows. If you are shooting carbons, and have been shooting these same ones for quite a while, you are ready for new ones. Carbon arrows, especially the more moderately priced ones, are notorious for having the spine go weak. Buy yourself some new arrows once and see what happens.

But even before that, learn a torque free grip. Oh, and don't look at the pin while you are aiming. Focus completely on the small spot you want the arrow to hit, letting the pin be in your secondary vision.