Fixing your sway

Start by using The Blueprint to draw a circle where your impact is. Place your ball in the middle of the circle. Take a stance, and check to make sure you're set up comfortably, not slouched over, and note where your feet are. Use some TRAQ Spray to mark your feet to ensure your setup and ball placement are the same with each swing.

Check the ball during your backswing - if you are moving your head position a lot, usually caused by a sway or changing your spine angle, you'll see the ball start to move "out" of the circle. A little movement is fine, but if the ball starts looking like it's moved a lot, you've moved out of your set up stance and likely are swaying. 

Take a few slow practice swings watching to make sure the ball does not move. Work your way up to 50% speed.