Teaching skill improves fastest through deliberate reflection, not just repetition -- delivering the same lesson poorly fifty times does not make it better unless something is examined and adjusted between attempts. A simple post-lesson reflection takes under five minutes: what worked, what did not, and what will change next time, ideally written down rather than left to memory, since specific details fade within a day. Student outcomes (who struggled on the formative check) and informal feedback (confused faces, repeated questions) are more reliable signals than a teacher's own sense of how the lesson felt, because it is easy to feel a lesson went well while missing that a third of the room didn't understand it. Ongoing development does not require formal training: observing a colleague's class, asking a peer to watch yours, or simply reviewing one's own rubric results over a term are all low-cost, high-value habits.