“Low-level disruption is wearing me down”

Almost nothing here would count as misbehaviour on its own. A whisper or a tapped pen costs a student nothing and buys a moment of company or rest, so a class of thirty produces a steady stream of them. Each one puts you in a bind: stopping the lesson makes the correction louder than the behaviour, and letting it pass teaches the room that the line is soft. Because you are watching for trouble, your attention flows to whoever provides it, and the students working well get none.

It holds because every part of it is defensible. Each student has done almost nothing, so firmness feels unjust, and letting it go is cheaper than dealing with it. No single lesson looks bad enough to force a change, which is how it wears you down. The techniques below take three routes in. Some strengthen your presence, from the door to the final minute, so drift is noticed early. Some change what your attention rewards, shrinking the correction until it barely interrupts and giving public notice to what is going right. And some make the consequence small enough to use every time.