Write for yourself. Even if in the back of your mind you're hoping to self-publish your book, or be discovered with a best seller. Don't confuse your writing with the need for approval. Write for honesty's sake. Write for writing's sake.
Write for the you who is free from the fear of judgment. Write for the you who comes in the door from work and wears the slouchiest sweatpants because they are soft and comfortable and you've worn them since college. Write for the you who wakes up in the morning refreshed before remembering anything that needs to be done for anyone.
Write for the you who puts French fries between the buns of the cheeseburger in spite of jeers from friends. Write for the you who plays 50s music and dances for hours. Write for the you who has cold lasagna for breakfast--straight out of the fridge, eating it with your hands. Write for the you who sometimes doesn't want to dwell on what other people think. Write for the you who is still innocent. Don't censor yourself because limiting your words and stifling your truth will not help you heal.
Write freely. Write to be free of the fear of what will happen when you write the truth.
I realize this is a tall order. If you are writing a memoir, write your life and turn it into art. If you are writing fiction, write the lie that tells the truth.