A good title is your book's first marketing tool.
A catchy, "selling" book title sometimes erupts spontaneously from the mind of the author, the editor or from someone in the publisher's marketing or sales department. More often, however, writing a book title--like everything else about thoughtfully publishing a book--involves work.
For the book publishing- and food-loving biopic Julie and Julia, about the best-selling cookbook author Julia Child, screenwriter and director Nora Ephron wrote a wonderful scene about writing a book title involving a lot of brainstorming and then an "Aha!" moment. Save for the invention of word processing, the scene rings true as one method by which book editors and authors think up their book titles.
A Good Book Title: The General "Recipe" to Writing a Better Book Title
Determine what ideas you want your book title to get across. Julia Child and her co-authors wanted to bring authentic French cooking to the American homemaker, who was likely to be unfamiliar with recipes or methods.
Keeping in mind the book's promise to readers, make a list of ideas of what you'd like the title to convey, and the emotional response you'd like target readers to have, and words that might suggest those ideas.
For example, if you've written a simple story to help young children start reading, your list might include:
Make the book sound appealing to reluctant readers
Let the readers identify with the characters
Reading isn't a chore
Reading can be fun
Make them want to read!