Don't drive clubhead at the ball; aim hands along arc of the shot
A simple but most important concept is the idea of the "aiming point," as described in Homer Kelley's illuminating book, "The Golfing Machine." Don't drive the clubhead at the ball, he urges; drive the hands at an aiming point somewhere on the arc of the shot. This may be just ahead of the ball, at the ball, or behind it. One can tell only by experiment. Fast hand speed will locate it, probably, behind the ball; slow hand speed, ahead.
The first time I tried this, using a driver, I found my aiming point an inch ahead of the ball. Then I drove my hands at and through it, forgetting the clubhead entirely. I hit the ball a country mile. With delicate little pitches and chips I have found it pays to aim not the hands so much as the left wrist -- the firm, bowed-out left wrist.
The Kelley book, by the way, is published by Star System Press, PO Box 15202, Wedgwood Station, Seattl e, Wash., 98115.