When I was a teaching assistant during grad school, my title was John. My students referred to me by my first name; my colleagues referred to me as John; my professors referred to me as John. My school friends referred to me as Juanito Cobos, but that was sort of an inside joke.
When I was a substitute teacher, I referred to myself as an "itinerant educator." I would go anywhere, and teach anyone anything, including things I didn't know.
These days, I go to the same place to work every day. My school district has 300+ students in it; I'm the only World Languages teacher. (A lot of other teachers work WL into their curricula, particularly in the younger elementary classes. And we're starting to do some more distance learning with WL. So I'm not the only one teaching WL. But I'm the only WL teacher.) Because of this, and because I teach all grades except PreK, I call myself "World Languages Department Chair." Really. I have business cards. (They're not for people who might someday be bosses or colleagues. They're kind of a gag.) These business cards used to say, simply, "World Languages Department," as in, "I am the World Languages Department." But people kept assuming that meant that I work in the WL department, not that I work as the WL department. Not grandiose enough. So I promoted myself. It was a very nice ceremony, if I do say so myself.
Now, thanks to this article, I think I'll start referring to myself as an "applied cognitive engineer."