PE and Recess
It is important when working on school culture to not forget about less structured academic times, such as PE and recess. These are times when emotions and (often) aggression are heightened, offering a perfect learning opportunity for social and emotional learning. Students often have numerous complaints about supervising yard duties, as they are vastly untrained in using SEL language and tools to resolve the disputes that happen frequently in these settings.
Here is a good basic article on SEL skill development during PE and recess. This article discusses the SEL skills of focus, emotional regulation, and goal setting.