I thought I'd post some of my very first attempts at flint knapping here as a means of encouraging others to have a go at it. The flint rocks came off the shore of a nearby lake as did the hammer stone - the big solid brown one.
I found it pretty hard to make any sort of deliberate shape but by striking at the edge of a broken piece of flint with varying degrees of force I was able to get a few very thin shards and some more useful bigger bits. The smallest blades were so fine that they tended to crumble rather than cut but the bigger items were ok for cutting vegetation.
The original flint core was then bashed a bit more until it became a palm sized chopper. It isn't very sharp but has a nice feel to it. I also managed to make a discoidal blade (left end of middle row) but the actual edge is mostly the chalky outer layer of the rock so it is not wonderfully sharp and will probably blunt really quick but it does have a sort of serrated effect.
I've got a cartoon book about flint knapping techniques on order from Amazon so when that comes I'll try to review it and give it another go.
But for now here is the mighty pebble chopper in action!