Because discussions are, by design, more free-form and student-driven than almost anything else we do, ideas for discussion classes are really more methodological approaches than templates. That said, here are a few structured exercises aimed at teaching the basic skills of discussion to students for whom the idea is new, followed by links to broader systematic approaches. I’ve tried to untangle those systems in this blog post.
Chalk Talks (Coalition of Essential Schools)
The handout on Participating in a Discussion Class I give my students
And not a discussion per se, but a way to get one off on a better footing: Question Exercise