So said Papa Hemingway. Actually he said: "the first draft of anything is shit". You don’t really know what you need to say until you have tried to say it. You may know what you want to say, but if that's all you say, it's just self-indulgence. You say what you need to say. You check the facts you are stating and the assumptions you are making. You search and delete clichés, urban myths, lazy short-cuts, waffle and boilerplate… and replace them with clear, simple ideas well-expressed. Mutatis mutandis if you are working in the visual arts.
Actors, dancers and musicians rehearse, soldiers, sportsmen and athletes train. Drafting is what writers, programmers, designers and artists do – or should do. Fashion photographers used to take hundreds of shots to get the magic for the cover of Vogue (now they take any old thing and Photoshop it to death). Painters scrape off the oil and start over, musicians stop the tape and record it again, movie directors do take after take of a scene. Because that’s the way you get the little flashes of magic that make it something to be proud of.