Golfers are commonly told to lock everything down and just rock their shoulders when they putt. The problem with that little gem of advice is, freezing any part of the body causes tension, which destroys feel.
Let’s focus on the head. When you try to keep it still, you create tension in your neck and upper body, and your shoulders don’t work properly. The result: You flick at the ball with your hands and arms, which is wildly inconsistent. To add fluidity to your putting stroke, you need some fluidity in your body, particularly your head. Except on very short strokes, it’s OK to let your head move fractionally away from the target from setup (above) to follow-through (below). That freedom keeps the putterhead moving down the line with the face staying square. You’ll hit a lot of great putts that way.