"There's no substitute for a teacher's quality preparation. Without preparation a teacher can't teach with purpose. This obviously refers to photocopies and supplies and crafting lesson plans, all of which are important.Full article: 3 Things Teachers Can Learn from Cooking, by David Kern
"But it also refers to the kind of preparation that involves contemplation. A good teacher reflects on both the subject he is teaching and his role as a cultivator of wisdom and virtue; he doesn't lose sight of (or ignore) the purpose of his calling. That is, he doesn't allow contemplation of the lesson plans to keep him from preparing his own mind and soul for the act of seed-planting."