It is over half the game. It is the quickest way to shave strokes off your scoring average. And once you learn to putt and create confidence in your putting, you will always have a feel to go back to and putt well almost every time. How do I keep from three putting on the greens. Three putting, as do any putting errors, comes from two areas, distance and direction.
Direction is the easiest to fix.
Learn how to align the clubface with your target by practicing two foot putts, straight up a slope. Distance is more difficult and where most people have putting problems. More three putts come from the first putt being too short or too far. Your goal is to putt a ball at each of those lines and stop the ball on the line. Repeat this process 5-10 times.