Hooking is really generally player's fault. When you see golfers who hook the ball, you'll find some common faults. If you hook the ball and want to fix it, see if you have any of the problems below.
1.Grip
The biggest cause for hooking is the grip that is too strong for you. You can read the book and grip it like it was illustrated but still hook the ball. The grip was too strong for you. So the correct grip changes from person to person. But generally, people who hook the ball have very strong grips.
Here is how you can find the correct grip for you. First, look at the left hand at address and see how many knuckles you see. If you can see 3 knuckles or more, rotate your left hand until you see 2 1/2 knuckles in your left hand. If you still hook the ball, try 2 knuckles.
Golfers sometimes forget to change the right hand grip. So try to rotate your right hand to the left as well to match your left hand. Feel like your hands are facing each other. If the V formed by your right thumb and forefinger points toward your right shoulder, try to point the V more toward your right ear. Some golfers have stronger right hand grip and weaker left hand grip. So pay attention to both hands.
2. Stop aligning to the right of target
Hookers tend to align themselves to the right of target because they hit the ball right to left. To fix your hook and start hitting it straight, you need to align your body parallel with the target line. I fyou weaken your grip, you will start hitting it right. After seeing the ball going to the right, you might think this grip is not going to work. But if you just fix your alignment, you might start hitting it straight with your new grip. So after changing your grip, you need to fix your alignment as well.
3. Ball Position
Hookers tend to put the ball more to the right to avoid duck hooks. The clubface is going to close at impact. So if your ball position is more to the left, the ball will go even more to the left. But if you put your ball too much right, you are going to swing inside out. The ball will start right of the target most of the time, so you almost have to turn the face over through impact. If this becomes your habit, you will have a hard time hitting it straight. At first, you might feel awkward to position your ball more to the left because you are worried you will hit it left.
But if you have a correct grip, your new ball position will help you swing inside in with a square face at impact. Your ball position has a lot to do with swing path. To fix your hook completely, you have to work on your swing path as well.
4. Face angle at address
Do you pay attention to the face angle at address? If your face is looking left of the target, you are likely to hit a hook. I know some golfers having closed face at address. They want to avoid right because they are aiming right to compensate for their right to left ball flight. So they are unconciously closing their face at address. Jack Nicklaus is known to hit a fade. He said he has an open clubface at address. He was aiming his clubface little right of the target to hit a fade. So if you want to avoid hooks or plan to hit it straight, make sure your clubface is facing directly to the target.
5. Shoulder Alignment
Shoulder alignment often determines your swing path. Hookers usually align their shoulders to the right of target. This promote inside out swing. Fixing your feet alignment might not be good enough. Pay attention to your shoulder alignment as well to fix your swing path.
Reference: http://www.golfsamurai.net/fault-fix/how-to-fix-hook.htm