
For anyone who cares about artistic process, you may find this post helpful. I rarely do anything of artistic merit without thumbnailing it to death first. In this case, here's some thumbnails for a scene in my book.
Thumbnails are fun in that you force yourself to reduce your idea down to a nearly stamp sized chicken scratch. Something about this forces me to think loosely and somtimes find myself liking the thumbanail so much that I end up scanning it, sizing it, printing it, and transferring it to large paper, simply because redrawing it would lack the energy and potency the thumbnail had.
Thumbnails are also helpful in plotting out scenes in your book, and helps you to get a bird's eye view on story flow and how everything is working as a cohesive whole.