In my opinion, paper tuning your bow and spin testing your arrows are two key tuning techniques for getting a fixed broadhead to fly like a field tip. I do like to line up the blades to vanes but I agree with those above, it has no effect. In addition FOC can effect your flight but you should see poor arrow flight using your field tips as well but not always. If you have paper tuned your bow, spin tested your arrows and you have the same results (which I don't think will happen) start field testing heavier grain or lighter grain broadheads.