Let's first make sure you're clear on the different impacts that cause different shots. When the ball is hooking to the left, that means it's curving in a right-to-left motion across the sky. For the ball to do this, it must be spinning in a counter-clockwise direction.
Imagine that the ball is on a peg, and that all it can do is spin one way or another. To spin the ball counter-clockwise, the club has to swing more to the right with the clubface pointing slightly to the left. In a golf shot, this is exactly what happens to make the ball curve across the sky in a hook flight. This can often be confirmed by looking at the direction of your divot. On the course, the divot will often be pointing right, with the ball ending up well left of the divot's direction. This is a classic hook.
Our discussion of the grip, stance, and swing will revolve around the different elements that can cause this type of impact.
The grip has little to do with the direction of the swing, but everything to do with where the clubface looks at impact.
Grips can be very individualized. A grip that produces a perfectly straight shot for one player can cause a huge hook or a slice for another. But you can make certain generalizations about the grip regarding hooking.
If your hands are turned too far to the right on the club, it's much more likely to return with the clubface looking to the left at impact.
Here's the guideline: In your stance, with the clubface square to the target, you should be able to look down and see no more than two knuckles on your left hand. If you see three or four, that could be contributing to your hook. Another guideline is to look at the "V's" formed between the knuckle and thumb on both hands. These should point somewhere near your right shoulder and right ear, no more to the right.
It certainly seems logical that if a golfer is missing often to the left, then before too long he or she would aim more to the right to compensate. With golfers who hook the ball, this is usually the case. But aiming to the right will cause the swing's circle to be too far to the right, exacerbating the hooking motion.
Double-check that your aim is not too far to the right, especially with your shoulders. You can lay a club on the ground, parallel to your target line, to check your aim. Or have a friend check your alignment. Just make sure that your feet, knees, hips and shoulders are parallel to that club on the ground, and therefore, to your target line.
Checking your stance and grip can often eradicate any hook without changing the hitting motion at all. Let the ball's flight be your guide. If the ball is curving less to the left, then you're on the right track. If it's flying straight or curving right, then your hook is cured.
There are numerous backswing issues that can affect your impact. For hooking, the two basic flaws are a backswing that is going too much inside or around, or a counter-clockwise twist of the shaft, or both.
If your backswsing is too much to the inside and not enough up, then the club is going to approach the ball on an angle that is too shallow and too much on the inside. In other words, too much along the ground. This swing direction will be a big part of spinning the ball counter-clockwise.
To fix this issue, take a look at your backswing at the top. Make sure the shaft is over your shoulder at the top, not too much behind you. To achieve this position, you may have to feel like the club is swinging a bit more up. You should also feel like your head is steady in the backstroke. No moving off the ball to the right! This will also make that backswing too flat and too much to the inside.
The next important element of the backswing is the clubface position. One of the biggest mistakes made by golfers who hook the ball is to turn the club counter-clockwise to begin the backswing. Unfortunately, this closing of the club simply creates a closed face at impact. The clubface should "open" on the backswing, relative to the target line. However, this natural opening is done with the turning of the shoulders and torso, not because of a twist in the hands.
When you are making your backstroke, just hold on to the club. No effort to twist or hinge the wrists should be made. When you get to the top, you can check for the proper position by looking at your left wrist. You should be able to lay a ruler underneath the face of your wristwatch and have it touch both your arm, and the back of your hand. In other words, the back of your left wrist should be straight.
With a good grip and stance, as well as a good backswing position, I'd be surprised if your hook is still here. If these first few areas check out, you're 90-percent of the way to curing your hook.
To begin the downswing, make sure you start down with a weight shift to the front foot and a turn of your body. While you are moving in this fashion, make sure you are tension-free in your hands and arms. This movement will virtually guarantee that the club is coming from the right direction.
If the ball still has a tail to the left, you can add this sensation: Try to get the feeling that the club is closing a bit too late. Feel as though the club is dragging across the ball with an open clubface. This should be done through softness in the wrists, with a feeling of letting the club swing. Some practice should give you the feeling.
The good news about working on this, or any other problem for that matter, is that you already have the best teacher in the world with you: namely, the ball. The way the ball flies gives you objective feedback about your swing.
You'll want to remember that you are improving if your 30-yard hook is now a 15-yard hook. No matter how strange a new move feels, always listen to what the ball tells you. You may be sure that the clubhead is staying open longer, but if the ball is still turning left, then you'll have to feel the club close later still. Not until you curve the ball to the right have you closed the clubface too late! The feel can trick you, but the ball won't.