Pace, path and putt. Lydia Ko is putting incredibly well largely due to the pace of her putts. Gary Woodland hasn't missed a 3 foot putt in 3 years. He hits up on the ball, finishing high with the putter face square to the hole and his pace is smooth.
Practice putting with your rear arm only. This will create the proper pace. It will also promote releasing the putter down the path to the hole. Practice 5 putts this way then putt with both hands on the putter. Drill and repeat.