It is 'customary' to hold the door open for someone who is entering a building behind you.
He did the work with his 'customary' efficiency.
She dressed in her 'customary' fashion.
(..) I'm... you know, I'm not gonna make any rules. We can, well, discuss it first, then vote on it. That's, of course... that's one way. And, well, we can vote on it right now. I think it's customary to take a preliminary vote. Yeah, let's vote. Who knows? Maybe we can all get outta here. (..)1957 12 Angry Men