Your stance should bend at the waist enough to allow your arms to hang vertically so your hands are directly below your shoulders, your feet are directly under your hips and your eyes are directly over the target line. Remember, the width of the stance controls the length of the stroke which determines the distance of the putt.
Grip pressure should be light enough that someone could pull the putter out of your grasp. The lighter the grip pressure, the better both hands work together. Your forward hand is your directional hand and your rear hand is your power hand. To avoid your dominant hand from taking over, only two fingers from your dominant hand should rest on the grip so overlap the last two fingers from your dominant hand on top of your other hand.
In order to maintain a Pure In Line Stroke, both palms should face each other while maintaining the same rhythm throughout the stroke.