The most common swing fault that I see in the swing is the swaying of the hips. What tends to happen on the backswing is that once the club moves back, the left knee and the left hip tend to move too much to the right. This also causes the head to move as well. The result of this movement causes 'fat' and 'thin' shots as the weight tends to stay back too long through the ball but also a reduced amount of power as the body hasn't turned effectively.
The key check marks on the backswing is making sure the clubface moves first and then the hips once once the clubface reaches the right toe. After the hips turn it is followed shortly after by the movement of the left knee. If committed to this takeaway, you will find that the lower half has considerable less movement than what you have done previously. When turning your body ensure the pressure stays inside the right foot. This will build up torque and enable the centre of your body to stay on top of the ball. This will enable you to build more power while being more consistent with your impact. The key also is making sure the left hip only moves maximum 2 inches off the ball.
The best drill when trying to eliminate the sway is place a SW under your right foot. You will notice that the shaft sticks up to the sky in around a 45 degree angle. Your goal is to make sure the shaft stays on that angle right up until impact which then the club will naturally fall to the ground when swinging through.
If you notice that the shaft angle drops down, it will mean that your hips have swayed and the pressure is now moved onto the outside of the right foot. Once you have practiced this drill, you will feel the sensation of turning rather than swaying.
If you need an further help in eliminating your sway, please contact me and we'll book you in for a lesson.