"Listen now. When people talk listen completely. Don’t be thinking what you’re going to say. Most people never listen. Nor do they observe. You should be able to go into a room and when you come out know everything that you saw there and not only that. If that room gave you any feeling you should know exactly what it was that gave you that feeling. Try that for practice. When you’re in town stand outside the theatre and see how the people differ in the way they get out of taxis or motor cars. There are a thousand ways to practice. And always think of other people."
— Hemingway on writing, via Brainpickings.