This capacity for studying a subject deeply is not only characteristic of composers but also of anyone who is creative. When creative people study a subject deeply they become curious about it, and as they become curious they start to ask questions, and as they gain answers they enrich their thinking. This enrichment is the fuel that powers their imaginations and launches their creativity.
If you want to enhance your creativity begin by studying the problem in front of you: dig into its history and explore its context; thoroughly rummage through areas related to it; greedily root out anything you can find.
If you become ravenously curious you will enrich your thinking and opportunities for innovation will form in your mind.