Knowing how the body should move in your golf swing is one of the factors that help to improve your game. The correct body movement will create speed in your downswing. Try this simple body movement exercise to help you understand what your body should be doing:
Make vertical line on your butt when you are in set up. When you impact, your butt should keep touch the red line.
If your hip off the line, it means your hip blocking the way where the hand through the ball. As you see the picture, when hip off the line it makes your club face open.
If your hip keep touch the red line, you will get more room for hand through the ball and it makes easy to release the club in correct timing.
After set up, put the ball between your butt and wall.
Now try to turn and turn when you turning if ball drop that mean is your butt is still of the line.
During turn and turn, if the ball not drop, that mean is your butt is stay still on the line.