The Problem: You miss a lot of putts inside 10 feet.
The reason for it: Your left wrist bends toward the hole just before impact and into your follow-through. This motion destroys your putting form.
The Results: The clubface closes before impact and sends the ball left, and you hit the ball on the upstroke, which causes it to skip off line.
Place your right hand on the grip. Now take your left hand and grab the inside of your right wrist [right], so that the knuckles of your left hand are even with or touching the butt end of the club. Swing the club back and through, making sure to keep the length of your backswing and follow-through roughly the same.
Notice how this drill immobilizes your left wrist and forces your arms and hands to swing through impact as one unit. This feeling will help you make consistent contact, which in turn will allow you to simply vary the length of your backswing and follow-through to propel the ball the proper distance to the hole.