Ann Lamott is one of my favorite writers. Her book, Bird by Bird (about the process of writing)is a DELIGHT to read. Here are two quotes that I enjoy in particular:
"It helps to resign as the controller of your fate. All that energy we expend to keep things running right is not what's keeping things running right. We're bugs struggling in the river, brightly visible to the trout below."
And
"Perfectionism is the voice of the oppressor, the enemy of the people. It will keep you cramped and insane your whole life and it is the main obstacle between you and a shitty first draft." (which, Ann explains, is important and unavoidable first step in writing)