Some more terminology nitpicking and then I promise I have something more substantive. Everyone’s pointed out that “CIS” should be lowercase and isn’t an acronym. I personally just took it as emphasis. But more importantly, it’s an adjective, not a noun. You’re not a cis. You are cis. It matters because referring to someone as a trans is generally seen as offensive. Either they’re trans or they’re a trans person.

And the language you’re looking for when talking about whether someone is “non conforming to CIS stereotypical looks” is that they’re “gender non-conforming”, which isn’t really about someone’s gender identity, but about their gender presentation. So cis people can be gender nonconforming and trans people can present as gender conforming. In fact, most trans people I know present pretty in line with a binary gender. Although, it’s been my experience that this is less common with teens in general, both cis and trans, and I know trans self-identification is higher among teens.

So I think in addition to all this, just minimizing gendered language with your students in general will be helpful. From experience, it involves a lot of thinking about the intention of what you’re saying and replacing the shorthand with the intention. So instead of “excuse me, miss”, you can say, “excuse me, I need some help” or “excuse me, this is silent time”. If someone isn’t responding, “can you get her attention?” could be replaced with “a tap on the shoulder would be appreciated”. It can be hard and not always immediately doable, but the habit is more important than any individual instance.

There’s also the issue of what to do when you do misgender someone. It’s common for people to panic and sputter and just generally not know what to do, which can be worse than the misgendering itself. Point of reference, it’s like forgetting someone’s name. It’s rude, but you apologize and move on. That’s all.