Here's an easy-to-remember four-word tip to help you pick up 20 extra yards: "Hide your left shoulder." Chances are that if you're not getting the distance you crave, it's because you're not rotating your body enough through the shot. In other words, you're hanging back just enough so that when the club is parallel to the ground on the follow-through side, your left shoulder is closer to the target than your right (when viewed from face-on). That's bad.
How can you tell if you've rotated your right shoulder in the follow-through far enough to hide your left shoulder? Take a look at the illustration below.
Check your right hip pocket—if it's even with the spot on the ground where the ball sat, as it is in the larger image on the left side, you're good.
If your left shoulder is still visible to a face-on observer as you swing into your follow-through, as it is in the smaller image on the right side, you're not rotating enough.
THE FIX: GET YOUR RIGHT SHOULDER TO THE TARGET
So how do you get your body to rotate a step or two faster? Simple: By rotating your right side toward the target so that your right shoulder is closer to the target than your left on the follow-through. This means that when viewed from straight on, the right shoulder will hide the left shoulder.
To encourage this full rotation, you want to have the feeling that your right hip, shoulder and lat are all moving in a counterclockwise direction through impact. Another way to think about it is to get your right hip pocket around so that it's even with the original ball position on the ground. Do this, and not only will your right shoulder reach the desired forward position, you'll release the clubhead properly and generate a lot more clubhead speed.