Start with your head square on your shoulders. Not tilted toward either shoulder. While in your shooting stance, turn your head to look at the target, draw. If you shoot with a vertical bow you're there. If you cant, tilt your head so that a line across your eyes is perpendicular to the string. That would be a tilt of the head toward your chest. In all cases, keep your predominate eye over the arrow. Don't think about "tucking" your chin. If you do the above, your chin will be in the right place. Good luck.