I recently chatted with an author who was having troubles coming up with a title for the fantasy novel she was working on. We threw out a few ideas, several of them good.
Then, I told her to try this: take a blank piece of paper and write down 20 titles.
Some of the ones she already possibly chose, of course, would make the list. But having them down on paper, in a way, clears the mind to brainstorm more.
If you're having troubles coming up with a book title or a direction on where the story should go or how to end the story or coming up with a book cover design (or countless other decisions), try the brainstorming method.
Take a blank piece of paper or blank document.
Then write down 20 ideas.
After the end of 20 ideas, put it away, and the next morning brainstorm 20 more.