Write like you write, like you can't help but write, and your voice will become yours and yours alone. It'll take time but it'll happen as long as you let it. Own your voice, for your voice is your own. Once you know where your voice lives, you no longer have to worry so much about being derivative.
The Kick-Ass Writer: 1001 Ways to Write Great Fiction, Get Published, and Earn Your Audience (ed. Writer's Digest Books, 2013) - ISBN: 9781599637730