2D Concept Design TLCWorkshop - with 2 awesome designers from Weta Workshop in New Zealand (of The Hobbit movies designing fame) and a guest visit by Iain McCaig (well-known, super-star, Star Wars designer)(You can read more specifics about this workshop starting here).
Paul Tobin, Nick Keller and Iain, I felt I learned a bunch about pushing design elements past my normal ruts/comfort zones. Ways to incorporate even *more* thematic elements and ways to research source material to help with it all.
TLCWorkshop, you really ought to treat yourself. They're pretty great, if I do say so myself).