Plato’s "Clever Butcher" Analogy
Plato has Socrates say, in The Phaedrus, that a clumsy butcher hacks to pieces a chicken and makes a mess of the whole thing, while the clever butcher recognizes that the chicken has natural divisions, joints, and divides it cleanly at those points.
The analogy to arranging one’s topic is rather obvious. Rather than teach people a laundry list of methods of arrangement (topical, spatial, logical, chronological, and so on,) I just like to cite Plato’s illustration, encourage them to find the natural divisions of the topic, practice and revise until it seems right, and "be brilliant!" People remember analogies better than laundry lists. (nudge, nudge, wink, wink!)