Pulling is due to poor alignment and not being square. Your hips are rotated to the left, your biomechanics faulty, you have an out to in swing plane caused by the body rotating too far left and if your centre of balance is too far left you will close the club face causing the hook.

If you are just rotating too far left with a square club face you will pull because of your poor posture. You think you are square but your shoulders will align left and overcompensate with your hip. If you try to square the hips on the downswing you will create a pull or push hook rotating the shoulder. Rotating more to the left will cause an open club face.

The diagram, (above right), shows the typical pulling posture with the centre of balance indicated by the red line. The faded image of a golfer dressed in blue is the correct posture. The correct posture should have a spine angle of 30 degrees, or as demonstrated in the diagram, at 11 o'clock or 1 o'clock depending if you are right or left handed.