Never be afraid to delete the piece of draft work which you think is imperfect. It is tempting indeed to keep it; for you had spent so much time writing it, deliberating the phrases and morphing metaphors, that you cannot bear to delete it all at once. You keep thinking that some part of it might be salvageable. Or maybe there are phrases in it that appear so beautifully crafted that you fear you might never discover them again. But these worries serve only to distract the mind. When begin writing afresh, all you will be thinking about is how to extract those pretty portions from the old draft and insert them in your present one. The result is an inorganic essay, straining to be original and full of awkward interruptions. Never be afraid to wipe the canvas clean.