There's a bit in Dave Trott's Creative Mischief where he talks about the practice he's adopted over the years of giving classes of students briefs to work on and having them come into the agency in the evenings to present their work to the creative department. As well as being wonderfully useful to the students he says this helps to train the copywriters and art directors:
"...each class is a crash course in running a creative department. Writers and art directors have just a couple of hours to look at up to 20 campaigns. In that time they have to work out what's right or wrong about the research, the strategy, the media choice, the creative idea, the copywriting, and the art direction of each campaign. And they have to be able to explain what to do about it in a clear, simple way. Great training in fast, powerful, clear thinking."
(Even better, Trott's art director Gordon Smith likes to have the campaigns presented one at a time - but he doesn't let the person who did the work present it. He picks someone else from the group. As it's the first time they've seen the work, their ability to explain it is a great test of how clear the idea and thinking are.)
As part of what I do I've been fortunate enough to do a fair bit of workshop-driven work with clients this year. It's taken me round the world and enabled me to meet lots of fascinating people so I count myself very fortunate. If I'm honest though, the thing that has surprised me most about it all has been the amount it has taught me about all kinds of stuff I didn't know before. Teaching, it seems, really is a great way to learn.