Dean Torges once showed me how to taper an arrow with a bowyer's edge tool. He drew a ring around the shaft at 3, 6, and 9 inches. He then laid the arrow on a piece of stock with a v groove running the length of it and a brad in one end sticking up just high enough to stop the arrow from moving. Now to the process... You start at the 3 inch mark and scrape towards the nock end, all the way around the shaft, rotating it after each pass, just enough to remove the mark, then move to the 6 inch line and scrape all the way to the nock, then from the 9 inch line. Once done, you only need a little hand sanding to remove tool marks and you're done.