is one of the ideas from The Creative Habit which I find particularly helpful.
The gist of it is something like this: insofar as you are a unique person, there are things which only you can create. There are also things which you will never create. In order to have the habit of creativity, you have to be in touch with your own scope of creative possibility. Everything that hurts you, everything that drives you, everything you hunger for, everything you love--all of it is part of your creative DNA. Your work will inevitably be a reflection of these parts of you. If you tend to choreograph ballets with a strong dramatic storyline and well developed characters, it's usually best to push yourself out of that mold a little at a time--or to work within it.
I love the way this helps me see my own repetitions as a way forward, rather than something that holds me back. Tharp writes about the way we know an artist by their repetitions--the common elements that carry through their different endeavors. Those repetitions are a source of power, style, and continuity. If there is something you're stuck on, it's probably deeply interconnected with with what you need to express. It may be something you need to work around for now, but someday, it may be the source of your best work.