I just found this so fascinating. From a link on the Drawn! blog:
The creation of an illustration promo
Australian illustration rep, The Jacky Winter Group, has posted a fantastic blog post detailing the six month process of how they put their latest massive promo together, from concept to completion: Six Months of Promo in Pictures. It’s a great behind-the-scenes look at how an illustration agency puts together an involved promo. Such perfect attention to detail!