I found a wonderful C.S. Lewis quote that elaborates on this -- I think he's spot-on, saying that as long as we tell the truth and stop worrying SO much about being original, we will be original. Because it's OUR truth that we're telling. And since every human being is original and unique, that will show itself in the work. Here's the quote:
Even in literature and art, no man who bothers about originality will ever be original: whereas if you simply try to tell the truth (without caring twopence how often it has been told before), you will, nine times out of ten, become original without ever having noticed it.
So brilliant, so true.