Decorative lighting. This adds visual sparkle. Whitehead advises using a single pendant in a square-shaped bathroom for just the right touch.
Putting a light fixture in a bright hue in an otherwise simple room can add some fun and interest to the space. Colored shades can work wonders especially when the light is turned on.
Instead of or in addition to sconces hidden lights can add a general glow that bounces off the wall and into the room in an even subtler and more diffuse way. Cove lights are built into niches that hide the light source (often a plain LED strip) but hidden lights can also be obscured by medicine cabinets shelving or storage units.