I use an empty filing cabinet drawer, and some space on top of some document storage boxes under one wing of my L-shaped desk.
I have a friend with a smaller office space that gets by nicely with a travel carrier for shirts and hanging clothes. The type that business people put their suits in and carry with them on an airplane? He keeps spare socks and undies in the bottom, and hangs a couple of pairs of slacks 2-3 shirts in there. It all hangs on the coat rack near the door, and looks like someone just got back from a trip. It works well.