Working on distant control is best when there is no expectation of making the putt. First, maintain grip pressure throughout the entire putt. As a warm up or practice drill putt to the fringe instead of a hole so there is no expectation of making a putt which aids in a relaxed grip. Practice strokes should be done while looking at the target so you are mimicking the length of the stroke required to roll the ball the proper distance. For putts inside 6 feet, look as deep inside the cup as possible.
Reading putts is important to getting the distance right. Determine the grain and slope by visualizing pouring a bucket of water and see what direction the water would flow. Learn to feel your feet to sense the slope as well. Once you are standing over the putt, committ to the target and putt with confidence. Control your misses by putting to the highest spot around the target. Misses on the low side tend to gather speed and break more. Remember, a shorter back stroke promotes the putterhead releasing down the target line.
Great warm up drill is practice from 6 feet by putting to the back of the cup, then the front of the cup and finish by making a normal putt stroke to the middle of the cup.
By the way, right eye dominant golfers should stand taller to get your eyes just inside the target line while left eye dominant golfers should be more over the ball so you are looking right down the target line.
There has been a lot of talk about tempo. Your tempo should match every part of your game. No slower, no faster. Doesn't matter whether you are making a short putt or a long putt. Let the length of the stroke to determine the distance the ball will roll. Use a bench mark formula of a 1 inch back stroke will roll the ball 1 foot up to 12 feet. Outside of 12 feet, the length of the forward stroke determines the length the ball will roll. For example, a 25 inch forward stroke will roll the ball 25 feet. Adjust the length of the stroke based upon factors such as slope and stimpmeter. Every inch the hole is above the ball add an inch to the stroke. Every inch the hole is below the ball subtract an inch from the stroke.