Chances are, you have a decent setup, but you struggle with the transition from going back to coming down. When people send me videos on Twitter, I see that a lot.
If you tend to slice--which is 90 percent of players--you probably hang back as you start down, pushing the club away from you and cutting across the ball. Using your lower body better can break that sequence.
From the top, make your first move a bump of the hips laterally, so that the side of your lead hip would hit a club standing outside your foot (above). Once you make that bump--with your upper body staying over the ball--turn your hips and swing through. That sets up a downswing from the inside, eliminating that out-to-in slice pattern.
Hank Haney is based at the Hank Haney Golf Ranch, Lewisville, Texas. To get fixed in Golf Digest, send Hank your swing on Twitter: @HankDHaney.