A really destructive error which most poor golfers find so easy to fall into and so hard to escape from is swaying. Going back, they let their bodies lurch sideways to the right like a birch tree swaying in a high wind—this, instead of pivoting the hips and coiling the body. Coming into the ball, same thing. They sag forward instead of correctly uncoiling the body. Of course, if you sway back, you're bound to sway forward. This being the case, the commonsensical thing to do is to find out what prevents a golfer from swaying back.
There are two major things that anchor the swing: the feet and the head. About the feet, first. If you set yourself up with a firm and balanced stance and then make sure that on the backswing the right leg doesn't sag to the right, then your right hip will have a pivot to turn on, and this gives your body a chance to coil properly. The other thing is to keep your head still. When you move your head to the right—as so many golfers do on the backswing—you move the whole upper trunk of the body along with it. Now, when you anchor your head over the ball, this discourages your body from swaying. On the backswing, your head is bound to move slightly, very slightly, as your shoulders turn away from the ball, but this is vastly different from allowing it to bob all over the place like a woman trying to spot a friend at the theater.
from PATTY BERG, St. Andrews, Illinois