In Summary:

When you are hooking the ball, the clubface is closed relative to your swing path. Here are three things you can do to help move away from this ball flight:

1)  Lag the club on the downswing.  Delaying the hit due to an increase in “lag” creates a face opening effect.

2)  Rotate your lower body quicker.  Rotation helps “steepen” your swing path during your downswing.  A steeper path will help to minimize clubface rotation through the hitting area.

3)  Create a line of extension post impact with your left arm and the clubshaft.  Achieving a position like this will help to prevent the clubface from closing down too early.