For a few unique feel in the bathroom, why not treat it just like your bedroom? Put up or sketch a design on the wall and place a small carpet beside or before the shower. Just be mindful that carpets can accumulate bacteria if left moist so make sure it stays clean and dry at least every other day. Take inspiration from this bathroom design that seems to emphasise the dark ambiance of the room by creating a raw feel of the environment. (If you have a weak heart and a wild imagination, I suggest you don't do exactly this to your bathroom unless you want to scare yourself every time you come in).
