Put the clubhead in the mitt
Many amateurs drag the clubhead back from the ball too far inside the target line, particularly with the driver. Here’s a great image that will help: Imagine a baseball catcher is holding a mitt three feet behind you, on the target line, at knee height. Starting back, simply try to put the clubhead right into the catcher’s mitt. By using this image, you’ll keep the clubhead much closer to the target line for a longer period in the backswing. This in turn gives you a wider arc for power along with a much better chance to return the clubhead to the ball on a path along or slightly inside the target line, resulting in more solid, powerful shots.