I finished a rewrite of part one of a novel recently, and printed it out with gaps in it for illustrations. Yesterday I found some time to fill some of the gaps.
It's a novel set in a world where animals talk, as they do in picture books. - I have been thinking about this story and working on it for over a decade now, and the universe it is set in is quite clear to me by now. It's a challenge to make it clear to the readers as well without overexplaining... I am starting to see why so many fantasy books come with maps and prefaces and appendixes.