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.
(..) Prepare yourselves. Sitting through the great games will be bad enough. For generations in the days leading up to the great games, it has been customary for our ruler to make the rounds of the lower pits to pay the fighters there the honor of her presence. (..)2015 TvShow: Game of Thrones Title: The Gift Season: 5 Episode 7