One way to improve your putting (particularly your consistency) is to practice putting while only using your right hand.
The purpose of this drill is to help you eliminate "breaking" your wrists while putting, maintain a solid follow-through and help keep the face of the putter aimed at the target.
Start by lining up a series of straight, two-foot putts.
Now, hold the putter in just your right hand. Make sure that your right palm is facing the hole. Now, ass you putt, maintain the extended wrist position on the follow through and hold the finished position for 5 seconds. Check to see that your right palm is square to the target.
Repeat this drill 10 times.