Our club conducts free fly tying classes for kids and adults every winter. We tie two flies per session and have 8 weekly sessions. First class is the Woolly Worm and Wooly Bugger. Final class is the Grey Ghost streamer, and a Catskill style dry fly. We take kids as young as 8, but find that, until age 10, kids generally lack the attention span to learn without constant supervision. We also do one "familiarization" class yearly, at an area university, and find that the 20 year olds there catch on very quickly, although most of them have never seen a fly before. Best of luck with your efforts.