I seen a buildalong a while ago and I really liked how he did his tips. He measured down an equal distance on both tips, and drew two 45 degree angle lines on each side a few millimeters apart. Then he cut each line with a coping saw, and pried the middle loose with a chisel. Then he proceeded to use files like everyone else.
I have switched to this method on the last few bows, and it gives me good consistent results.
I'll try to find the thread and link it but I can't remember what it was called or who made it. Maybe somebody else can remember.