That reading is more important than writing. That reading the classics matters. That if reading for you is not narcotic, quit now while you are ahead. (Why would you want to write a book when you don’t read them?)
That you should write the novel you want to read, not the one you think you can write. Write the book you think you can’t write—for writing is the act of pushing past yourself.
Do not care for what the establishment wants because the establishment is built of writers who once set out to dismantle it. Learn that if your writing sounds establishment, it is already dead.
Write dangerously. Write for the deepest part of yourself. Never write looking over your shoulder.
Accept failure as the essence of process and rewrite your way through it.
Learn discipline. Learn self-reliance.
Write past your limits—that every draft is more intelligent than its predecessor. You will be a smarter writer when you finish your first draft. By the time you finish your tenth draft, your writing will be smarter than you.
Learn to read your writing objectively.
Learn to read your writing aloud, for it allows you to hear your writing as if another wrote it.
Learn that tone is everything. Spend however long it takes finding the song for your book. And then keep going back to those perfected early pages to remind yourself how your book is supposed to sound.
Learn to get closer to what you are writing about. Learn to get closer to truth. Ask yourself all the time, am I close enough? Can I get it tighter?
Learn to cut. Learn to cut what’s left. Learn to get your writing to the point at which you cannot better it. That is the time to show it to somebody else.
Learn to trust your opinion and know what you want. But know there is a time for good counsel.
Learn to be kind to yourself, because writing is hard and it will bash you up.
Learn that you are not in competition with other writers. That your only competition is time, which is the truest judge.
I'm a merciless cutter, which I suspect is a struggle for many writers, but this same merciless quality shows up when it's time to be kind to myself, which I rarely am.