You Can Teach Writing has an interesting post, Formal Assessment by Proxy, on peer coaching.
Along with a definition and description, Aragoni includes discussions of when peer coaching will work well and when it will fail.
One of the successful hints is that there should be minimal reading.
The questions are short, focused. Even students who read poorly can learn the drill by hearing the questions a few times.
I would not have thought of that one, even though I am used to reading the essays to my students to make sure that they “get” them.
One of the failing techniques I also would not have thought of.
Infrequent use. Like all writing strategies, peer coaching has to be done often enough that students memorize it so they don’t have to consult their notes.
I recommend the whole article, which was recommended by Dr. Lee Skallerup of College Reading Writing.