OK. Here's a copy of what I wrote the other day in the coaching library, amended for the big hook. This is how I think of the action I use.
You will need pretty good ball speed to control the big hook. So consider the height of your backswing, which may need to increase to accommodate this.
Swing
Once the ball has reached the apex of the swing, you need the ball to be "turned out", that is, the ball slightly faces away from your body, with your thumb pointing outward. This allows the weight of the ball to be suspended in the stronger side of your hand and locks the ball onto your thumb which now faces perpendicular to your swing plane. The ball does not turn back in until it has passed your hip before release, allowing you to maintain a fairly relaxed thumb. This is essential for the speed of release required. Your thumb will need to fly out, loose as a goose!
Wrist turn
Keep your arm behind the ball so that the inside of your forearm stays facing foward/upward. You only turn your wrist. (While reading this, put your arm in front of you and try this out while watching it. You’ll get the idea and the feeling pretty quickly.)
The advantage of learning this is that you can learn not to overturn the ball.
Hint – Do not commence turning your wrist until after the ball has passed the thigh of your non-sliding foot.
Finger lift
As the ball approaches your ankle, your thumb leaves the thumb hole, giving you have a limited period in which to apply finger lift. This is called the release window. You can increase the release window with practice. This is simply closing your fingers (resisting the weight of the ball) as you rotate, but can be muscled up a bit if you like with time and training, although this really isn't necessary these days. (I've spent the past year taking the muscle out of the release from ye olde urethane ball days.)
It’s all one smooth action. To see a magnificent example of this, watch Pete Weber win the 2006 Etonic Championship on Youtube. Yes, it will require practice and good instruction and a bit of hand-holding by a coach will help.
Good luck with it.
Cheers,
Jason