Good shotgun marksmanship begins with proper preparation, which includes ensuring you have a properly fitting gun, adjusting your choke and ammunition combination for maximum performance, practicing sufficiently, mastering shotgun techniques on leading the target, and especially learning to estimate ranges.
Shooting Stance: Use a relaxed, balanced stance with your feet shoulder-width apart and your weight slightly forward on your left foot (if you are a right-handed shooter). Slightly bend your left knee, and lean your body in the same direction.
Pointing: The shotgun is designed to be pointed at moving targets that can appear suddenly. Your eye must be in line with the barrel and the sight, which is usually a bead. (Matching the gun with your dominant eye is critical.)
Shouldering the Shotgun: Bring the shotgun to your cheek first, and then settle the stock against your shoulder with your eye above the centerline of the barrel.
Trigger Pull: Quick trigger action is necessary with a shotgun. Quickly press the trigger with a firm motion, keep a firm grip while pulling the stock rearward, and only tighten your trigger finger. Do not tighten your whole hand as this will throw off your shot.
Follow Through: Continue the shotgun’s swing as you pull the trigger, pivoting from the knees and not the waist. Stopping the swing as you shoot will cause you to shoot behind the target.