Here's a drill that transforms golfers into more consistent ballstrikers and longer hitters. The most remarkable aspect of this drill is that it doesn't involve swinging a golf club at all, but I feel strongly it best teaches the athletic movements involved with swinging a club.
Pick up a golf ball, assume an imaginary address position and then toss the ball underhanded at a specific target no more than 10 yards away. Simulate a golf swing by making a weight transfer to the right as you wind up to toss, turning your back to the target and releasing the ball as you'd release the clubface at impact.
A golfer who slices will invariably make an underhanded toss to the left of the target. I've seen amateurs do it time after time; they fling their right arms across the body, mimicking the outside-to-in path of their golf swings. They also allow the right foot to spin out as they make the toss, instead of transferring their weight to their left foot.
Any golfer who can make the proper motion with the underhand toss–right arm folded in an L position at the top, right palm open at release, knees touching at the finish in good balance, the ball starting slightly right of the target–can incorporate the same athletic motion into his swing.
Art Sellinger represents the Four Seasons Resort and Club in Las Colinas, Texas.