At our dojo we are lucky enough to have teacher's training classes which are run by Bruce Bookman sensei and which meet once a month for 2 hour sessions. These classes are open to 1st kyu and up with an occasional 2nd kyu by invitation. It's like a kenshusei program (what I understand of that, at least) in that it is a committment to teaching and training and not at all a casual, drop in thing.
Each of us teachs a handful of techniques to the other members of the class while sensei watches and comments. Then the group analizes what could have been better in terms of execution of the technique or transmission of the info or anything else. It's a great way to develope a critical eye. It can be brutal and more than one teacher has dropped out. But it's a terrific honor and everyone is really supportive and energetic. We all look forward to the 1st Saturday in the month. Plus, there's usually a special seminar (bokken, jo, randori...) on the same day so we get to feel like uchi deshi for a day before going home to the spouse and kids or whatever.
Also, as part of the program, we sign up to teach a beginners' class where sensei watches while we teach the whole thing. This is good because picking and teaching techniques to an all yudansha class in not the same as teaching an average class in our dojo.
On another note, we have a large kids' program and those teachers start out as assistants and work into having their own classes over time.
Anyway, I am a life long teacher and so I take my teaching very seriously. Except I love it so I'm not always that serious when teaching, especially the kiddos!
Kinda long winded, sorry,