and then everyone else is like "oh shit. I guess I should include my pronouns too" and follows suit, helping normalize and encourage the behavior.
this is one of my favorite examples of a sociology lifehack: set a perfectly polite and casual example of good behavior, and anyone who wants to be in your ingroup will usually follow suit. ymmv depending on location/culture/exact interaction, but it's one of my favorite methods to employ as a disarmingly charming trans person. I've done it multiple times in group therapy, and it works like a charm every single time
my DBT therapist likes to call this kind of thing "positive emotional manipulation." everyone who is in DBT is extremely good at emotional manipulation because it's a survival behavior we learned in response to trauma, but emotional manipulation can be used in positive and socially acceptable ways-- and knowing the difference between the two is part of dialectics and effective communication. so you better believe that every time I do it in group, he notices and gives me a sly grin