If you struggle with direction or controlling the side spin of the ball (slice or hook), then you will need to control the face angle at impact. The number one influence of face angle is your grip. If the grip is wrong, then you will struggle squaring the face of the club at impact without making a poor mechanical move on the way down.
The image below shows 3 "preferences" in grip...this means you can pick one and it will be correct. There is not one right or wrong in the 3 choices, it is just a preference of what feels best for you.
For 80% of golfers, a proper "stronger grip" will help:
- Prevent pushes to the right
- Reduce left to right ball flight
- Hit more square shots (center face)
- Pick up distance
The image below shows a neutral and strong grip. Although technically this image is true, I disagree with the "x" over the too strong grip, because that all depends on your ball flight.
Assuming your ball flight is straight, a neutral grip will do. However, for 80% of golfers who struggle with the fade or slice (left to right ball movement), I would recommend a strong grip.
If you slice, simply make sure 3 knuckles or more are visible on your left hand as you address the ball. This essentially allows the club face to close (or square) easier through the impact zone. Just make sure when you rotate your left hand to create this grip, also move the right hand to match the left. You know the hands (or grip) match if the crease caused by the thumb and hand run parallel, as shown in the "too strong" image below.