Tom Kelley and David Kelley, founders of Stanford's Design School and IDEO (the industrial design firm that made things like Apple's first mouse and the standup toothpaste tube) have a great book, Creative Confidence.

Here's their website for the book, along with some tools and useful instructional videos https://www.creativeconfidence.com/tools/

+1 agreed, Creative Confidence is an insipiring book.