Take your putter and set up 4 or 5 balls. Start hitting putts longer than 3 feet but shorter than 60 feet. Just find a tempo that you like. Once you find it, count it out. Using a count of one, two. Or one, two, and three. Regardless of the length of the putt or the swing, maintain the same tempo. Tempo is the pace, rhythm is the sequence, and timing is what holds it together. If your tempo changes, the rhythm changes, which means the timing also has to change. This makes it impossible to be consistent.