I see a lot of amateurs holding the club too tightly. I notice it most when they try to waggle. The movement looks stiff and short.
To swing correctly, the right amount of grip pressure—and where you apply it—is important. You should feel the club being supported by the last three fingers of your left hand (above, left). Those fingers should grip the firmest. My longtime teacher, the late Stan Thirsk, used to remind me to keep the club in the fingers of my left hand and never let it slip into the palm.
In the right hand, the middle two fingers do most of the work. The forefinger and thumb of the right hand should feel relaxed. In fact, I've seen many great players, including Ben Hogan and Fred Couples, practice with those two fingers clear off the club (above, right).
Back to waggling. With softer grip pressure, your waggle will be looser and will help relax your hands and arms. During the swing, the right hand should be free enough to fire the clubhead through the hitting area.
When it comes to gripping the club, how tight is too tight? Here's an exercise: Next time you practice, try backing off with your grip pressure until the club is almost falling out of your hands. Then firm it up just enough so you can control the club. That likely is your ideal grip pressure. Will it feel lighter? I'm guessing it will.
Tom Watson is a Golf Digest Teaching Professional.