You can drastically reduce your golf score if you learn to putt properly. One of the most important tips I can give you is to relax while putting.
Yes, this goes for all shots but I want to emphasize it when it comes to putting.
We have all blown a putt at one time or another due to lack of confidence. Put your hand down. We all have. 
Follow this tip and it should help you relax. Line up your putt with consideration as to what line the ball is going to follow. Now put everything else out of your mind. Concentrate on stroking the ball.
Don’t worry about the contour of the green after you have lined up your putt. You figure that out when setting it up.
Don’t punch the ball. The follow through is just as important here as it is when hitting a drive or fairway shot. Follow the putter head through on the same line the ball has to follow.
