Better players often fight the push-hook, where the ball starts out to the right, then curves hard left. They either drop the club too far inside on the downswing or thrust the hips toward the ball, changing the spine angle. Both faults move the swing path out to the right, usually coupled with a closed face (above).
Try keeping the chest down throughout the swing with a low finish, maintaining the spine angle till the end. For a drill, stick a shaft or alignment rod in the ground in front of the ball parallel to your club, then swing under it (right). Your hands must stay low, which keeps them from moving out and away -- the classic hooker's move.
*Matt Killen, one of Golf Digest's Top-20 Teachers Under 40,
is based at The Club at Olde Stone in Bowling Green, Ky. He works with Kenny Perry, J.B. Holmes and a number of other tour players. Read more about Matt Killen.