Kevin Cornell’s illustrations have become a trademark of A List Apart. In an article on Bearskinrug he explains how he approaches the job of illustrating, taking ALA as an example.
Reading about his design process you can’t help but see definite parallels with web design. In particular is the concept of preliminary sketches done in the rough and in black and white - identical to the idea of wireframing in greyscale to prevent clients fixating on colours. One approach I found useful was that he charges for revisions to ensure revisions are meaningful and kept to a minimum. This is something I’ll be taking into my process - perhaps the first 2 revisions are free and subsequent ones are charged at a fixed rate.