I make my arrows so I "draw to the head". In other words I draw till the head touches my bow hand. I have two sizes only. 25" draw length for the bows I shoot with a slight cant and an anchor point and 22-1/2" draw for the Native American replicas which I draw and shoot with thier style.
Drawing to the head is an excellent way to do it, in my opinion because: you have a built in "trigger" mechanism, The arrow length helps establish "muscle-memory", and once knocked there is absolutely no reason to pay any attention to that arrow (no sneek peek's to interupt your concentration)
Anyways, that's just how I do it,
rich