In general, practicing the three basic skills of putting will help minimize the number of three-putts, but even the best will have to deal with this reality of the game. Three putts happen!
Practice the things that matter on the greens. There are three basic skills.
First, learn to line up square and be aware of your clubface angle. Do this by hitting short putts with alignment sticks. Make ten in a row from three feet to stat every day.
Next, learn to develop a feel for distance and confidence in your distance control. There are a number of drills available that will help you in this area. For example, my favorite is our number one exercise in Blind and disabled golf. We hit progressively longer putts, without a target, simply by constantly increasing the length of the swing, focusing on distance only. (go to oldeschoolgolfschool instagram for the all-time best 1-minute distance control putting drill in golf)
Next, learn to read greens. Use common sense. Be aware that most greens slope from back to front. Meaning everything behind the hole will be quick, anything to the right will turn left, and putts from the left should go right. Also, watch chips and putts from all players in your group until the ball stops. Learn from experience!!! Have a plan before you hit your putts.
Ultimately, becoming a better putter through good practice sessions is the only answer!! It takes time and effort to learn to putt well.