Ball position starts in the middle of your stance, then begin with a slight wrist hinge, followed by a chest turn.
Get the grip in the fingers of your hand, and you can now move the putter better.
Check out this great drill to understand why a routine is so important for your putts.
Let the putter arc and allow the shaft to rotate, allowing the putter to come square at impact.
Find an old hole on the putting green, and place tees one foot behind the tees. Try to get each putt to fall within the foot at the hole and behind.
Setup square to the putt and then at contact strike the ball with the clubface open or close, this will help to know what "square" feels like.
Take your normal setup, and just before the swing, take your thumbs off the grip.
You can do this drill anywhere, put a pen behind the ball, make strokes with the putter going over the pen.
Use your legs in the swing and you can maintain the energy and balance in your swing.
Place an alignment rod under your grip and make the motion with wrist hinge and rotation.
Do not worry about the hole during this drill, pick a spot and do not look until the ball stops, and find out where the ball ends up.
Master one technique and then try to switch the club for a different situation.
Some great putters don't have their eyes over the ball when putting. Try standing up taller, arms hanging from the shoulders, and then change your eye position to inside the ball.
Imagine that your caddy has set the putter for you, then fit yourself to where the putter is.
Focus on one very specific point in front of the hole, maybe just even a blade of grass.
Use a yard stick to understand how your putts start.
Understand how the weight of your putter can change how your handle different green speeds.
The last time your eyes leave the hole and back to the ball, start the stroke right away!