One of the simplest ways to make your bathroom interior design unique is to use a catchy wallpaper. Not only is it easy to apply (you just have to peel it and then stick it), it's also budget friendly idea. Just add several stylish items like a shiny mirror and a sleek sink and your bathroom will be an instant conversation-starter for your guests. On a final note: color black will look especially good in a bathroom with a lot of natural light.