Tip From the Archives
You want to improve your swing path.
The easiest way to groove a good swing path is to swing without a club. This allows you to focus more on how your arms are moving along the target line.
Focus on swinging your leading arm so that it is inside of the target line during the backswing. To help encourage this motion, set up in front of a doorway so that your leading hand is brushing against the door jamb. Swing your arm back into a full backswing and swing it forward without touching the door jamb. The thought of smacking the door should be encouragement enough to keep your swing path along the inside of the target line.