I want to give a shout out to a book by an editor colleague. Elizabeth Lyon is a longtime editor and teacher at workshops. You may find her book valuable. Here's the blurb from the Amazon page:
If you are writing a novel, you probably have a "working title," and you think it's pretty good. Friends and colleagues may agree. In over thirty years as a book editor and writing teacher, I can promise you that nine times out of ten, working titles are rarely the BEST.
Best titles can gain immediate attention from literary agents, publishers, and readers. Best titles sell books. If you discover an extraordinary title, your novel may become unforgettable.