This is a great tip to add height and power to your shot.
Experiment with a Weak Grip
In my experience, a weaker grip adds power and height to the average golfer's shot. I recommend at least experimenting with this grip. When you take your grip, V's should be created between the thumb and pointer finger of your right and left hand. For example, I'll use the right-handed golfer. Most golfers learn from the beginning, to make both of the V's created point at the right (back) shoulder. The result is a fairly strong grip. Here are the steps you should take if you are interested in trying a weaker grip.
1. Put the strong grip on the club. (Both V's pointed at your right shoulder)
2. Don't move your left hand
3. Keeping your right pinky in place, unlock the rest of your right hand, and rotate everything over the top of the grip. Your left thumb should be totally enclosed by your right palm. Now the V formed by your right hand should be pointed more at your head, or maybe even toward your left shoulder.
This new grip is going to feel strange at first, and may not work with your particular swing. But with certain swings, this weak grip is the missing link.