Visualise.
See the ball traveling towards the hole and coming to rest next to the hole in your minds eye just before you putt.
Its a great little tip for helping your body to judge just how hard to hit the ball, try it and see what happens.
For a more technical tip its all about the length of your backswing and follow through, hold watch and feel after you have putted and memorise the length of the swing you used and how far the ball traveled.
Think pendulum…a small pendulum for the short ones and a bigger pendulum on the longer ones.
Good Golfing
Anne