I've had dream teaching - my first recorder teacher has to stand out there: he does have some postnominals, but more to the point he took someone who had an enormous dollop of musical self-doubt, and turned her into a musician who not only loves her music, but can now make her instruments do something of what she wants them to, enough to make her feel she can express herself, and also share that with other musicians and an audience. From a might-manage-grade 6-at-a-pinch, to a very sound ATCL result, from don't-make-me-play, to yes-I'd-love-to-do-a-concert.
How did he do that? I wish I knew - it ought to be distilled

. I needed confidence and encouragement, and to be taught how to practise and how to pick apart what I was doing, as well as to learn a sense of rhythm and how to listen. The first two I think he probably gave me by acknowledging what I had done, and never giving an impression that it was poor, but still finding the way to show me how to do this better. Practice skills had not, until then, really been taught to me by any of my other teachers, though I'd learned a bit from my kids' piano teacher. I was aware from what he did when accompanying me, of what listening skills he has, but I probably learned those more from ensemble playing in the end: both he and YAP, who accompanied me for my LTCL, are so good at adapting to a soloist that I was accommodated to, instead of learning how to fit in: no criticism for either there, they're just consummate musicians.
I'm not sure that it necessarily follows that those who play best will also make the best teachers, but if I were thinking of which player's skill mix I'd most like to have, it'd be Dan Laurin, for his unbelievable neatness at speed, and flexibility of sound and expression, which is utterly wonderful

.