One of the keys to becoming a great iron player is making good ball-turf contact. It's also one of the hardest things for many players to do. For most, the club bottoms out too early and hits the ground behind the ball. The clubhead slows way down and is moving upward through impact, producing a higher, weaker flight.
Ideally, the bottom of the swing with an iron--where the clubhead hits the ground--is a few inches in front of the ball. To achieve that, the handle of the club needs to lead the clubhead into impact. For that to happen, the lower body must shift toward the target at the beginning of the downswing. You also should turn your hips in conjunction with the shift at the start of the downswing to get your weight to your front foot. Now your hands are leading the clubhead into the ball, setting you up for flush contact every time.
Hank Haney, a Golf Digest Teaching Professional, runs the Hank Haney International Junior Golf Academy, in Hilton Head.