I often create the title from part of a meaningful quote from the story. It's a method I often find used in books and one that can be particularly effective. For example, in Eclipse, by Stephenie Meyer, there is a VERY meaningful sentence in which the character Jacob tells Bella that, essentially, they could have had a great future together before the vampire Edward fell in love with Bella, and that Jacob could have been her sun, her sky, but Edward is an eclipse, and what is the sun to compete with an eclipse? Therefore, the title was based off this vital line, and the book now stands as Eclipse. Try finding several sentences that carry a lot of meaning in your story and take several possible titles from them. Narrow the list down until you are satisfied with the chosen title.