The Mishna Berura says that the only reason to put them in one’s pockets is if when you go amongst the goyim and they will be cut/defaced.

the mishna berura also says that if necessary you can put them in your pockets. but those who put them in their trousers, he says, its not enough that they are embarrased of a mitzvah, but they themselves are defacing them as they get ruined there.