For the last few months I have a youngster (4yo) who was feral until last winter and although I'm inexperienced in the art of teaching youngsters I have found it rewarding and frustrating in equal measures! The good bits stems from his love of life, his willingness to learn and the joy of seeing him progress. The challenging bits are him:
Rearing occasionally when leading to field - that's an ongoing lesson and he's slowly getting better (I now lead him out with my husband leading the older horse who just plods along amicably which seems to help the situation)
Teething and chewing of any object - reins, leadropes, tools, humans, towels, fences, rugs etc. And the times I've had to pull out bits of arena surface from his mouth - sigh! I now use a leadrope with a chain attached to the headcollar so it is less pleasant to chew.
Getting bored in school (I keep the sessions short & vary the work as much as possible)
Testing the boundaries - yesterday I got the ears back snaky face for no apparent reason so I had to remind him quickly, firmly (and kindly) who was boss. It hasn't happened since (although I suspect it might do!).
Certainly (I think) having a strict routine has helped enormously as well as having an older quieter horse on board. The youngster has just been amazing in terms of adapting to our routine and appears to be flourishing, happy and relaxed. Couldn't wish for more really!