Use these little reminder cards to silently redirect behavior in your classroom. If a student is not behaving, silently place one of these cards ("Stop what you are doing and make a better decision.") on their desk.
This is a great classroom management strategy because it reminds students that they can choose the correct behavior and you can administer them silently.
I would also recommend printing these and having them laminated. Explain to your students that when they receive one of these, they should correct their behavior. They should also return the card to you at the end of class, giving you the opportunity to discuss how they could choose better behavior in the future.