When it comes to smaller spaces you're not exactly spoilt for choice. According to interior design expert Kathy Kuo, founder of Kathy Kuo Home, the best bet is placing your mirror above the sink "at a height that works for just about anyone standing normally and looking straight ahead." That said, you can double up. "Hang two smaller mirrors on walls that are diagonal or kitty-corner to one another," says Kuo. "Mirrors are a great way to add light and depth into a space that might otherwise feel crowded."