I'm sure you've seen the innovative new field guides from Richard Crossley. They're great, and you should all go here to purchase them.
What you may have missed, though, is that Crossley's groundbreaking collage style did not begin with field guides. Crossley worked out his stylistic kinks during his career in the advertising industry. I've done some deep research and found some of Crossley's ads, all of which show his style in development.