Rule one of fandom: there are some things that only exist for us.
Don’t send actors fics
Don’t give them explicit art ever
Don’t tag them in rpf questions or theories
Don’t try to bring them into fandom drama of any kind
Don’t hold them responsible for what the producers and writers decide
They’re still people. They have private lives, which do not include fandom.
Don’t insult their hair, clothing, etc and then tag them in it. And especially don’t do it to their face.
Don’t ask them if they want to kiss their costars
Don’t ask them about ships.
If a couple of actors are jokingly insulting one another, that is not an invitation for you to join in.