Well since I decided to start making long bows I figured might as well try my hand at knapping flint.  Bought some dacite online and watched a bunch of videos.  I would say it is the hardest thing I've tried to learn how to do.  I so far have made a lot of gravel and a few trinket heads, one or two that I might put on an arrow and see how they fly.  Fun hobby and hopefully I can get better at it and make them thinner and try and take a deer with them this fall.