Bright idea for unexpected lighting: Look for opportunities to install light fixtures in alcoves tray ceilings and wall niches to trace interesting lines. Notice the hidden lights in the ceiling alcove above the cylindrical fireplace mantel here.
The light fixture should not be your only consideration — the type of lightbulb is equally important. Halogen compact fluorescent and LED bulbs come in a range of warm or cool hues. Much like the color of your walls the type of glow you want is mostly a personal decision. If your walls are covered in cooler tones you might want to warm them up with a lightbulb that casts a warm glow. Conversely you may want a cooler glow to brighten up a darker space.
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.