I'd say maybe food, drinks, maybe some fast food places if you go out and eat occasionally. Maybe do one worded things like "down" "up" "right" "left" etc. There's actually an app called Avaz that does this exact thing for nonverbal people. It helps me when I go nonverbal if you don't actually want to make cards.

Seconding the Avaz suggestion! But if physical cards are your best option, I would put some basic needs like "I'm hungry/thirsty" or "I need the bathroom". Mood indicators might also be helpful. Sometimes common stims can be misinterpreted as signs of distress, so being able to quickly communicate your mood might help reduce unnecessary concern or attempted intervention Since you said it mostly occurs when you are overstimulated/stressed, definitely include cards that briefly describe helpful interventions if you are in distress like "I need to be somewhere dark and quiet", "I need DPT", ect.

I think it would also kind of depend how long episodes usually are? For example, if you’re nonverbal for, say, more than a day, you might want or need expanded cards. Especially if you have to be in different environments (a school or job might call for different cards than home). If episodes are usually much shorter, some of those might be irrelevant. Generally I think the most important ones are covered though.

Definitely put ways that you need for comfort or to ground yourself. Any fidgets or comfort items. And maybe even things that you don’t want/ will make you feel worse.