Problem: The player has a problem having the correct face angle at impact when putting.
Result: Missed putts, and poor contact.
The Drill: When putting, one very important fundamental is acceleration. However, this acceleration must be stopped quickly after stroking the ball, or it can lead to additional and unwanted body movements. The hit and resist feel is something that all professional short distance putters have incorporated into their stroke. So should you!
Take two tees, and place them firmly into the putting surface, leaving enough room for a ball to roll through. Place a ball between the tees, setup and perform your stroke. Your club should stop at the tees; focus on trying to hit both tees at the same time, as this means your stroke was square. Furthermore the feel of hitting the ball and resisting the follow-through is something that should greatly help your short putts. Give it a try!