Once the sensation of balance in the bow arm is understood, the same principles can also be applied to the left hand.  As with the right arm, as soon as the left arm is lifted away from the trunk of the body, it is either completely suspended from the shoulder, or the weight can be partially supported by the the string and the fingerboard at the point where the finger meets the string.  The two exercises in this first video help us to understand the sensation of supporting arm weight in the finger tips.

Once this sensation is understood, our task is to apply it to the fingerboard as demonstrated in the following video.