Impact Drill Golf

What are some exercises to create a golf club face closed during the descent?
I need advice on the reason that my clubface is open at impact. I have a videotape that shows me how open my clubface is at impact, and I would like some exercises.
Assuming you have a good golf swing .... somewhere between the beginning and end of your back swing, you simply turn your wrist. I think the best tool to use to discover the problems of oscillation is a large mirror so that you can watch and view positions before aside. Swing idling in front of a mirror while paying attention to your wrist (front side view, etc..) And you will soon determine when where the opening of the club face occur.
Clubface Golf - Impact Drill part 1 of 3