1) To establish control in large classrooms, teachers should set clear communication rules upfront and provide phrases students can use to participate respectfully. 2) When first encountering students, teachers should convey confidence, status, and firmness through posture, eye contact, relaxed poses, and formal but unambiguous instructions to establish authority respectfully. 3) Teachers should address misbehavior with a pause and serious tone rather than shouting, and rewards should be used sparingly for significant efforts that exemplify values rather than often.