After years of "on again, off again" golf, I'm renewing my committment to improve my game. I'm a high handicapper who has never developed a consistent, confident swing. I'm sure there are many problems, but through video analysis of myself I think I've identified the major problems: coming "over the top" on the downswing and not rotating my lower body to generate leverage/power. This is producing weak and inconsistent iron shots. I'm a big guy (6'3'' around 205 lbs.) but I don't hit the ball nearly as far as I think I should.

Can anyone recommend some good drills to help promote the correct move from the top of the backswing into the proper downswing and on through the ball? As I said, currently I'm getting no power from my lower body and seem to be coming over the top with my clubhead.

By the way, I'm a lefty but I'm used to reversing right and left on any instructions.

Thanks!