In a frame
Keep the wooden dowel connected to your shoulders with the rubber bands. Step into a door way. To get the feeling of how the shoulders should turn, you want the wooden dowel to hit the door frame during the backstroke and through- stroke. The important part is that it would hit higher on the door frame than where it started at address. If you then watch the putter head, you will notice it is moving inside your target line on the backstroke, back to the target line at impact and then back inside the target line in the follow-through. You will also notice the putter face will slightly open in the backswing, back to square at impact and then slightly close in the follow-through. Like I have said before, the putter should move on a slight arc. Practicing your putting stroke in a doorway will groove that arc.