Think the biggest factor that can prevent bad shots is to take the time to pick a spot. If you take a minute to look at the animals vital area, you will see shadows and curves and color variations. Even the elbow. Aim at a specific shadow or hair and that way you will not be aiming on the whole vital area. You will instinctively hold your pin on the target point if you pick a spot. If you don't your bow will shoot all over the place.

Also, don't nobody be trying to fling long shots. Get close.

Nic