First you will need to download a FREE Metronome App, the specific one does not matter as long as you can set the beats per minute. Watch the video below a few times to see what it looks like...

I set mine to 72 beats per minute.

Using the beat or click from the Metronome swing the putter back and forth like you would during a normal putting stroke...several times

Make sure the putter is at the ball on the beat. Keep time for several strokes...putter face at the ball each time. Start the putting stroke on the beat to set the tempo,

Here's the secret that makes this work, for short putts the motion is slowed and shorter in length but the beat is the same. That means for long putts using the SAME BEAT just longer/faster strokes.