I use a bow square and set the nock 1/4 over 90 degrees if I have no idea where to start. I say that because if I have to put a new string on and on the previous string I have the nock point set at 3/8 ths over, then I will start with 3/8 ths over on the new string. I ussually will not go under 1/8 over 90 or over 3/8 ths over 90 degrees for various reasons. If I need to do that I may make other adjustments like change the arrow tip weight, change the arrow spine, check my tiller (make adjustments as needed).