When working on interactive interfaces for a very small team, I have to wear a lot of hats. One thing I find useful is developing a UX prototype concurrently with illustrations and graphic design because doing an illustration for a book and doing an illustration that functions as an interface have slightly different workflows.  Here's another prototype with more detailed, though still rough, artwork. I'm using the Adobe XD preview to test whether what I'm doing is on track before sinking a lot of time into a detailed illustration and having to change things because of UX considerations.