If your hook or slice persists after trying several solutions, it's time to experiment with varying the thickness of your grips.
Hooks and slices often result from poor hand action -- either too much or not enough. And the thickness of the grip can be a major factor in promoting or inhibiting that action.
Too thin a grip can lead to too much hand action, which causes the hands to roll over through impact, closing the clubface and resulting in a snap-hook. A thicker grip puts more of the club in the palms of your hands, minimizing hand and wrist action.
Too thick a grip restricts hand action. The hands don't release through impact, and the clubface stays open, causing a slice. Thinner grips place more of the club in the fingers, increasing hand and wrist action.
Experiment with grip size only as a last resort. Most of the time your hook or slice follows from poor fundamentals. Try hitting clubs with grips of varying thicknesses and see if they make a difference in the accuracy of your shots.
Private Lessons 1999 Times Mirror Magazines, Inc., used under license by GolfServ Online, Inc. Instructional information provided by Golf Magazine.