The simplest - although not the easiest - golf secret is ''swing the clubhead.'' Swinging it as if it was a weight on a string, the string being attached to your swing center in the spine.
If you learn ''true swing,'' its exponents will assure you, the clubface will automatically square itself up by the time it collects the ball. You yourself don't have to do anything about it.
Long experience has taught me, however, that this is so only with two provisos: (1) That the grip is right, with the clubface ''square'' at the address. And (2) Provided you swing the clubhead through to a full finish.
A short swing requires hand action. Only a full-finish swing will correct itself automatically.
As a morning exercise practice the body movements that go with a full finish. From almost a standing start, swing the left shoulder up and the right shoulder down then both round until the right is ahead of the left and your right foot is up on its toes.
Do this regularly, 10 times or so a session. Get your body used to the full-finish feel. Then on the practice tee, or on the course, using a minimal backswing, sling the clubhead over your left shoulder several times to get the clubhead used to it.
It is the finish that is the secret to swinging.