Although I've never taught luthiery, I've had apprentices as a carpenter, taught high school (ugh - note to self - just keep breathing...), undergrad college students and many years of self defense and verbal intervention training. I have to say that I LOVE to teach, its very dear to me and I've put a lot into it.
A couple of hard and fast that have applied across the board for me in all areas include: 1. teaching for the love of the work - if you love it, it will come through and that's half the battle and 2. teach to your own goals, not the students'. And what I mean by the last one is that if you set out to have a person learn what you have taught them, you're destined for frustration. People learn what they want when they want through their own preferred channels. Like JC said, set out your curriculum and make sure it is well known what will be taught by you as opposed to 'learned' by the student - there is a difference. That way, you have your own teaching goals that are independent of a student's success or failure. Of course, no one wants a failing student, so we work to their weaknesses by building on their strengths, but one cannot own another's experience if you know what I mean.
Carpentry is pretty straightforward to instruct - there is room for creativity, a lot, but it's pretty much just lego on a bigger scale with more complicated and dangerous tools. Luthiery I would compare more to teaching martial arts. Students want to learn for a very wide variety of reasons and typically all come well-prepared with grandiose illusions of what will be accomplished along with a nice overestimation of their experience and ability, so that needs to be planned for accordingly!
What you teach will involve straight technique, tool work, etcetera, but will also have to include the creativity and personal touches that i'm comparing with martial arts. Who we are and how we conduct ourselves in the world impacts the outcome of our creative endeavors (duh) and some will have no interest in the more stylistic components or will simply be incapable of performing to a level of what you might consider 'basic skill', while others may outshine you on the first day and leave you feeling like you're playing catch up the whole time!
Some of the best relationships I've ever had have been fundamentally a student / teacher relationship and many of them continue to teach me today even though I've had no contact directly for years. Fundamental to those great relationships is unconditional positive regard on behalf of both parties - this is a rewarding attitude to carry.
And of course, pay no mind to George Bernard Shaw's quote "those who can, do, those who cannot, teach" as he was referring to rebels and revolutionaries, not instructors. To teach successfully, you need to be the expert, and those who inspire us most when we learn usually are...
