'You can't judge a book by its cover' so says the idiom. But I would suggest that in our highly visual world where we are constantly being bombarded with so much visual stimulus, that this idiom is largely outdated. Making a choice based on a visual aesthetic is integral to many daily decisions. A book cover is, therefore, a tool for creating a starting point for a story that will unfold within.
I have a real soft spot for books and the thrill of creating a book cover never seems to wain. The selection below is a mix of trade and education, concept and final designs that I've created over the past 10+ years.