Below are three favourites of mine.
Good writing is rewriting - Truman Capote
Write. Rewrite. When not writing or rewriting, read. I know of no shortcuts - Larry L. King
We are all apprentices in a craft where no one ever becomes a master - Ernest Hemingway
Do you have particular on-writing favourite quotes?
Write the first draft for yourself, the second draft for your reader and the third draft for your agent. Can't remember where I read it, but it clarified the process of polishing a manuscript for me.
You don't have to write what you know, write what you feel - Lee Child.
“I don’t want to write for adults. I want to write for readers who can perform miracles. Only children perform miracles when they read.”
― Astrid Lindgren
“The books we enjoy as children stay with us forever -- they have a special impact. Paragraph after paragraph and page after page, the author must deliver his or her best work.”
― Sid Fleischman
“Who is more to be pitied, a writer bound and gagged by policemen or one living in perfect freedom who has nothing more to say?”
― Kurt Vonnegut
“You have to write the book that wants to be written. And if the book will be too difficult for grown-ups, then you write it for children.”
― Madeleine L'Engle
“We have to continually be jumping off cliffs and developing our wings on the way down.”
― Kurt Vonnegut
“There are three rules for writing a novel. Unfortunately, no one knows what they are.”
― W. Somerset Maugham
“I hate writing, I love having written.”
― Dorothy Parker
“The only way you can write the truth is to assume that what you set down will never be read. Not by any other person, and not even by yourself at some later date. Otherwise you begin excusing yourself. You must see the writing as emerging like a long scroll of ink from the index finger of your right hand; you must see your left hand erasing it.”
― Margaret Atwood
"Suppose that a person writes what she must. That is only the first step of becoming a writer. The work must survive the moment of creation. It must get out to an audience. She or he must dare to show the work. She must risk ridicule, misunderstanding, scandal, condemnation, & what's often worse, none of the above: silence. No attention at all."
― Marge Piercy