Sconces come in many forms from artistic and ornate to sleek and simple and can hold just one bulb or many. Single-bulb sconces that are spread farther apart will add light around eye level for more even brightness. For the total elimination of shadows pairing two-light fixtures spaced closer together will achieve a salon level of clarity.
The most common use of up lighting is in a recessed cove around the top perimeter of a room. To maximize light output use a T5 fluorescent or LED light source that will wash the ceiling with light. This helps to create a brighter ceiling that bounces and reflects light throughout the space without glare. Combine this with lots of natural daylight to increase the overall light levels in a room.
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.