There are key fundamentals that all great putters do very well. Some of these include having a correct grip, making a consistent motion with the putting stroke, and knowing how to control speed and read greens correctly.
Holding the putter correctly in the palms will help you make a better, more consistent putting stroke. You also want to have good grip pressure. Feel like you are hanging onto the putter grip securely but don't grip it too tightly because that will restrict the swinging motion.
With your putting setup, you want to have your feet about shoulder width apart or just slightly narrower than that. The ball should be played slightly ahead of the middle of your stance. It's important to have your eyes directly over the golf ball in your setup position, this will allow you to see your lines more easily when putting. Allow your arms to hang down relaxed and it's okay to have the arms bent when putting.
The shoulders are primarily what makes the putting stroke. The hands and arms hang on but the distance between your elbows should not change while putting. Try to maintain the triangle with the hands, arms, and shoulders when putting and your putting stroke path will be consistent. There is not really any wrist break with putting and you want to be in a position to allow the putter to swing freely on a good path.
Reading greens is a skill that can be learned by anyone. It's helpful to look at the whole green while trying to determine how your putts will break instead of just looking at the line between the ball and the hole. Pay attention to high and low points on the green. Also, the ball will tend to break towards water and bunkers. Looking at your putt from the opposite side of the hole is very helpful. You'll always get the best read from the lower side when you read it from both sides.