Crisp Contact Every Time From Johnny Miller (The ONLY golf drill You Need!) 

I would agree with that statement. You basically want to brush at the ball or in front of the ball on the downswing. I've started doing this more and more lately as a practice swing. Especially with uneven lies like uphill and downhill. It has hugely improved my ball striking and chipping. It helps me with ball position so I stop hitting uneven lies fat or thin.