BibliOdyssey, that fount of the wonderful and bizarre, has posted a great series of illustrations by New York based illustrator Yuko Shimizu in two or three stages of progression.
These are usually a draft, final line and then final color version of the image. BibliOdyssey author peacay asked Shimizu for copies of her draft versions and put them together with the finals as sets.
The post is called Yuko’s Progressions. Click through to the Flicker postings, and then to the large size to see the details (images above, with my detail crops below).