I've noticed over the years that if i arrive at a site for this coaching at 9 am, and people start setting up the environment described below at 9 am, it can take 30-60 minutes of fussing around to get things ready. Therefore, please *COMPLETE* ALL of this the day BEFORE.
While working on the real (usually messy legacy) code, coach developers in how to break dependencies, test in isolation, and do TDD.
2-7 developers, plus coach.
We should start on an method or function that that you would like to "bring under test" -- to be able to unit test in isolation, so that we can do unit TDD. The method should NOT be trivially easy -- it should have some dependency problems, because teaching dependency breaking is a point of the coaching. On the other hand, it should not be the most awkward, messy, highly dependent method you can think of -- that would make getting started too slow.