A couple of elastic bands could teach you a lot about how you strike the ball.
Hitting the sweet-spot with your putts is perhaps one of the most underrated skills in golf. An inability to consistently hit the putter off the same spot on the putter-face almost always leads to poor directional control and poor distance control, especially on long putts.
Not consistently striking the ball with the centre of the club-face will often rob us of our natural touch. We may leave a putt well short and then compensate by blasting the next one by, when the only fault was a poorly struck first putt.
Try this cheap and simple trick with a training aid the next time you practice your putting (which I sincerely hope you do if you want to improve your golf).
Put a couple of elastic bands (blu-tac works just as well) either side of the sweet spot of your putter. Now, hit the middle of the putter and there is no problem. But hit the elastic band and the ball will instantly deviate off-line.
Set the elastic bands at a width where you can strike 80% out the middle of the putter-face. When you have achieved that, make the drill harder by moving the bands closer together.
Repeat until you achieve 80% again. This is a great drill that can be practised at home or on the putting green and will help lower your score.