If you tend to slide ahead of the golf ball, block the ball out to the right or slice this can be a real simple little idea that can work. What you do is take the logo on your golf ball, this is a range ball, and you put the stripe back here on the right side of your body. When I put the golf ball down and set up I can just see a little bit of that logo on the back of the golf ball. The idea here is when I go up to the top and come back to impact I want to see that logo. If I slide in front of the ball on my downswing I will lose sight of the logo and I will know for sure that I once again moved ahead of the golf ball. So put this logo down the correct way and it will really help you when you are moving ahead of the golf ball.
Jim McLean runs the Jim McLean Golf Schools, considered by some the world's finest. He is listed as one of Golf Magazine's Top 100 Teachers and Golf Digest's #3 instructor in the world.