I had that problem and overcame it by increasing the tension on my release, hooking my thumb on the rear/side of my neck, and only touching the release with my trigger finger while holding my other three fingers straight out. I also draw and sight on deer I don't intend to shoot just to help me get used to this sight picture. This helps me because I know from the outset that I am not going to actually shoot the deer and lets me concentrate strictly on my form. I also always use a life sized deer target to further reinforce the sight picture for when you are actually shooting at a deer.