One of the reasons people will hit the ball on the bottom of the club rather than in the center of the club is that during the swing they will tend to either stand taller or pull away from the ball, bringing the arc of the swing up with them and thus catching the bottom of the club, or what we call thin. What you would like to have happen is that whatever posture you start with you would like to be able to maintain that posture, keeping the same distance from the ball throughout the swing. So that you will have the same distance from the ball at the top of the backswing, at impact, and into the first part of the follow-through as you had at address. This will allow you to make solid contact. We have a drill that will help you to do that. What I would like you to do is to take a tee and place it behind the ball just a couple of inches outside the target line. Then I would like you to take a pen and place it in your mouth. Then, while hitting, try to keep the pen pointed at the tee throughout the swing. You will be able to tell if the pen moves up or if the pen moves down, or too much to the right or to the left. If you can do this making half swings then it will help you maintain your distance from the ball as you swing. Let me demonstrate. This is how you maintain the same distance from the ball throughout your swing, allowing you to make solid contact with the ball rather than hitting it with the bottom of the clubface.