Designing a Book Cover

One of my mother’s favorite bromides was “Don’t judge a book by its cover.” As personal philosophy, the words have a strong moral base. As a marketing tool, they are worse than useless. Everyone judges books by their covers, even those who say they don’t.
It used to be that most people browsed bookstores and/or libraries to find their next read. How to choose? An author you know and like is always a good bet, but what if you are looking for something new? A trustworthy friend’s recommendation...