There was a good article in this website's magazine, volume 17, issue 3, which demonstrates how to spiral wrap fletchings to arrow shafts. The author, Neil Wilhelm, also uses pitch to secure the fletchings but I found the wrapping technique illustrated in this article works quite well even without using pitch. Since I don't use pitch I have to pin the arrow shaft up against my kitchen counter with my body when tying on fletchings. This frees up both my hands for tying on the fletchings.