In order for me to keep my string hand relaxed, it has to start relaxed and stay relaxed all during the draw. It doesn't work for me to haul back on the string and then try to relax my string hand after I come to full draw. So I start my draw with a very light touch of my fingers on the string, and feel my hand stretch out as I apply tension to the string. I try to get the feeling of starting my draw with the muscle right behind my shoulder blade, so that my forearm and string hand are just links in the chain, reacting to the force of my back muscles but not adding any force of their own to the draw.