Write about what it’s really like to be inside your own head. What are your concerns? What are your relationships like? What are your feelings? Do not interpret anything. Just describe what you do and what your friends and parents and teachers do, and what you think when you do it. Do not tell us what it means. Do not take any shortcuts. Get as detailed as you possibly can. When there are feelings, try to say what they are like by comparing them to other experiences you have had.
Never use anything you have heard anyone else say (unless it’s a character saying it). No sayings. Nothing like “clean as a whistle” or “smart as a whip” or anything else people say all the time. If you must make a simile or metaphor, use something that you relate to in your own life. What is the cleanest thing you’ve ever seen? Ok, clean as that. Who is the smartest person or thing you’ve ever seen?
Write to yourself. Write about everything you know. Don’t write about anything you haven’t personally experienced. Resist the urge to copy something you’ve read—either a plot idea or a voice. Speak in your own words. Only use your own words. Don’t try to be anything or anyone else.
Your story will arise out of your own life. Once you get a sense of the story, you can add wishful thinking into it. If that has fantasy elements, cool. If you wish things in your life could have happened differently, then imagine them differently. But start with what you have experienced for real.
Do not worry about what to talk about. Talk about your own life. That’s it. Do not talk about how you feel in any way, shape or form. Only describe feelings and thought. Never name them. Do not say you felt love. Describe what you do that made you think you felt love. Never tell anyone you felt love. Describe what you did and people will draw their own conclusions. That’s what you want.