Add a little decor in your hallways full of doors, and help your guests find your bathrooms.
The bathrooms my guests use upstairs and down are both in walkways with two or three doors. To alleviate the "try a door until you get the right one" phenomena, I hung a "Powder Room" and "Toilette" sign on each door to help people find the rooms with a little less confusion. Plus they are a nice decoration where there is no wall space to decorate.
I found mine at Hobby Lobby and Ross and hung them with double sided foam tape. They've hung for years with no incident of falling.