The Correct Position of Your Hands (Grip) at Address
When you set up to the ball, you change the width of your stance depending on your club. The width of your stance is the widest with your driver. But you take narrower stance with your irons.
Some tour pros change their stance width in an effort to control the distance.
Anyway, one the things you might want to be careful is the position of your hands at address when you change the width of your stance.
The Position of Your Hands don't Change
One of the things Jack Nicklaus always asked his coach to check was the position of his hands at address.
No matter which club he was using, the position of his hands didn't change. Whether he was using his driver or wedge, his hands were always in the same position.
To be exact, his hands were toward the inside of his left thigh.
The position of your hands at address has a big impact on your ball flight.
In this site, I recommend you to position your hands toward the inside of your left thigh like Jack Nicklaus did.
But if your hands are more forward than this position, you tend to hit hooks. If your hands are too far back than this position, you clubface will tend to open during the golf swing and cause slices.
I like to point out one more thing.
If you take your address and notice that your hands are in front of your zipper (this will likely to cause slice), you might try to move your hands forward.
But this probably won't stop your slice.
To position your hands correctly, you might want to move your hand to the correct position and re-grip your club. I think this is very important.