TIP FOR YOUR GRIP: Set your left thumb on the back side of the grip and your right one on top.
If you hit a lot of slices, you should "strengthen" your left-hand position on the club. All you have to do is grip it more in the fingers, as opposed to the palm. Do this, and your thumb will rest on the back side of the grip (1), and you'll see three knuckles on your left hand when you look down at address. This will help reduce the amount the clubface is open at impact in relation to your swing path—and lessen the left-to-right curve of your shots.
What about your right hand? Keep its position closer to neutral, with the thumb sitting more on top of the grip (2), like when you shake hands. Many people believe the hand positions should mirror each other, but when you take a strong left-hand grip, doing the same with the right will close your clubface too much at impact. You'll start hooking or pulling shots left of your target.
It's no mystery why some players, like Paul Azinger, use a strong left-hand grip. It's an anatomical thing. When they let their hands hang by their sides, their palms practically face behind them (right). If your grip has always felt awkward, let the position of your left hand as it hangs dictate how you hold the club.
Sean Foley, a Golf Digest Teaching Professional, works at the Core Golf Junior Academy, outside Orlando.