This would make a great procedure (Harry Wong). Count to five or hold up one finger at a time when the class needs to refocus. Discuss what occurs for each number at the beginning of the school year and eventually the reaction will be automatic.
My co teacher had the best idea! We made a nose wiping station. We set up a mirror, shelf, tissues and a trash can. The kids can look I the mirror and see how to wipe their noses. We will use it later for emotion cards and other exercises!