I bet you thought that you were going to get a nice, short answer -- well, no such luck. There are three things that need to be illuminated in a home: art, architecture and people. I like to make sure that the lighting, first and foremost, is complementary to the homeowners and their guests. If the lighting is designed primarily for the art, you get a museum effect. Certainly, art and architecture need to get their fair share of the spotlight, but my goal is to always let people be the stars of their own homes. I even have my own personal follow spot. Effective lighting is layered lighting. In addition to the accent illumination that is used to highlight art, tabletops and greenery, there needs to be an ambient source to soften the shadows on faces and fill the room with an inviting glow. There also needs to be task and decorative lighting. Task lighting allows homeowners to do work, such as cooking a meal, shaving, applying makeup, reading or dressing (but hopefully not all at the same time). Decorative chandeliers or pendants, on the other hand, are the architectural jewelry. They should add sparkle without overpowering the other elements of the overall design. The color of the light source is very important, as is the heat and ultraviolet (UV) radiation it emits. While artwork tends to read more true in color rendition when illuminated with a bulb that is closer to daylight (5,000K), many art-lovers lean toward a source that is closer to incandescent (2,800K). If the tonality of the art reads in the warmer hues, a lower Kelvin rating enhances those colors. If the art has greens and blues, consider a higher Kelvin rating, otherwise the colors may get too muddy. Most light sources emit heat and UV rays in varying degrees. Natural daylight is the worst offender, followed by incandescent light and then fluorescent. Most art collectors know to protect their art from the sun, but they may be less aware of what the other sources of illumination can do to their collection. It is a good idea to add a UV filter when using incandescent or fluorescent sources to illuminate artwork. LEDs, now emerging into the market with colors close to daylight and incandescent light, don't emit UV rays, so they are very safe for art. There is also a huge difference in the life of these bulbs. A standard household bulb lasts 750 hours, while a compact fluorescent lasts 10,000 hours. LEDs claim to last 30,000 to 50,000 hours. Even if you operate an LED for 24 hours a day, 365 days a year, it would still take three to six years to see if they last as long as they allege. I just don't have the time.