I teach at a secondary school, where adolescents are sensitive to being embarrassed. I take this into consideration and try not to say thins that would embarrass my students, because i have seen where they become disrespectful themselves. whenever students became disruptive in my class, I stop doing what I am doing until the disruption stops. Most of the time, that works once. If I stop for a student more that once, I ask the student to meet me after class to discuss the bad behavior and what behavior is expected onwards. Most time, that works for me.