My approach to classroom norms has shifted dramatically over the last 7 years. Before that I had been carefully constructing my norms to cover every eventuality. This largely stemmed from a desire to be transparent and clear about my norms and to have a response to parent queries about how I handled misbehavior in class. What I found, however, was that while it might help with parent queries, kids couldn't even remember the most basic parts of my rules, even if I posted them on the wall and made students study the rules and followed that up with a quiz. They didn't even remember when we practiced the rules before really enforcing them.
What my students did sniff out and remember vividly were my priorities. So make your priorities clear to yourself and clear in your rules, but also make them visible in your daily routines and words. As stated before mine are student mental health and Latin reading proficiency. I think you can see how they are reflected in the rules I have settled on for the moment.
These are the rules I have settled on for the moment:
Supporting and respecting each other in learning:
Stay focused. Because I rarely give work outside of class, you will need to be an active participant in class to learn the language.
Be Helpful: Please do everything you can to actively support the learning of others.
Be Kind: Please do not put someone in a mood that makes it hard for them to learn.
Be Honest. Clear and honest communication helps us all know how to best support each other in learning.
Common sense rule: There are things that, although not expressly prohibited here, are still not allowed. For example: Throwing something out the window, recruiting classmates for your shady bitcoin scheme, and irritating Ms. Holt when she is hungry. (remember that kids might have a different culture's common sense)
Really important note on enforcement:
Simple, clearly articulated and FLEXIBLE rules are an important aspect of a trauma-informed classroom. More importantly though, being curious about why students are acting out is essential. In my experience students almost always act out when they are feeling unsuccessful in class. If I see a student breaking my norms here are the questions I ask:
"Do you have a question?"
"Why don't you want to do (the thing we are supposed to be doing)?"
"Are you ok?"
"Do you need to take a break/walk/ or go to the school counselor?"
This might also be a good indication you need to reteach the lesson the next day. This plus pacing via exit tickets has almost eliminated discipline problems.
If you do really need to deploy a consequence I recommend the 5 min detention after school. It's annoying enough to be a deterrent without making your relationship with the student antagonistic.