When the time comes to find yourself as a writer, IF you've learned the many (endless) rules of writing fiction, forget about them. IF you've learned proper grammar, forget it. Here's the reason for this suggestion. Your writer's voice comes from your self-expression, and if your self-expression sounds like a textbook's rendering of "how-tos", the formality of knowing writing rules will forbid your true voice from exposing itself.
Maybe you've been conditioned to believe that perfection is achievable by obeying the rules. It's not. Even if you were able to conform to all of them, the end result would be stiff and robotic. Writing fiction means you create story. You use everything to express yourself. You find what works for you. You make that story yours.
IF you've learned the rules, you can eliminate all that don't apply and write your story the way you must. Otherwise it won't really be yours. Instead it'll be a formulaic, predictable piece of writing. One that will be easy to forget.
Father, thank you for providing each one of us with what we need and requiring we learn how to walk our talk. In the Name of Jesus, Amen.