Teaching Editing

Are there any fresh, exciting approaches out there to the teaching of editing and proofreading? I'd be particularly interested to hear from anyone who conducts workshops where students work on their own writing.
I do a generic workshop for postgraduate research students from across our university, with presentation and demonstration of principles, some group activities using examples (some of them, but not all, from real thesis drafts), and provision of resources to refer to for grammar, punctuation, spelling etc. Fairly standard, and it works ok, but I feel there must be a better way (perhaps I've just been doing it for too long).
Jan