If you tend to reverse pivot or have a limited turn, then you may need to work on your separation. There should be able to separate what you upper and lower bodies are doing. If you are limited in separation, where you can turn your upper body independently from your hips or vice versa, you cannot create a winding effect with your muscles. This exercise will help you learn how separate you top and lower halves.
Lie on your back with your knees in table top and your arms extended.