This story is for you if...
• You often hit slices, pulls, and pull-slices.
• You never think about your takeaway; you just sling the club back.
If you're prone to swinging over the top, you're likely whipping the club to the inside on your takeaway by moving your hips more than your shoulders. The trick is to move your upper body first, then your lower. That's tough to do from a static position, so try this drill.
Set up like normal, hover the club over the ball and then swing it forward with your shoulders and hands. Once your hands reach your left hip, swing the club back like it's your real backswing. After a few tries, you'll get really good at swinging the club back without it whipping to the inside. A good checkpoint is that the club points straight up when your arms are parallel to the ground.