One of the most common causes of that pull shot simply occurs in the set up. People that pull shots tend to set up with the right side too high. That is, the right shoulder is too high and the right hip is too high so that the right hip is too far over the right foot. What you would like to have happen is you would like to set up with your left side higher than your right so that as you make your swing around that angle the club will tend to swing more inside out. So when you get that set up we call that a Reverse K where the left side is higher than the right, the left side looks like it is in a straight line and the right side looks like it is indented. A good exercise to help you get that feeling is to set up next to your golf bag. Just put your foot your knee and your hip next to your golf bag. This makes the left side real long and tall and sets the right side underneath more. As you make your turn around that spine angle your swing will go more inside out and thereby eliminate that pull shot.