In this article, I will discuss the first principle of lighting design: layering. When you set out to produce lighting in a room, you should first set out your task lighting and your accent lighting, and only then set out your decorative and ambient lighting. This enables you to put together a highly functional and beautiful room that people will enjoy spending their time in.
First, you should set out your task lighting and your accent lighting. Think about what exactly you plan to do in a room. If people are going to read in a room, then you should first set out your reading lights. Similarly, in the dining room, light your table for eating and then any sideboards that are used for food preparation. Don't forget to light things that are only sometimes used, like having reading lamps in your bedroom. After you've done this, you can add accent lighting, which highlights various aspects of your room. For example, if you have artwork you'd like to light, light that, and light anything in your room that you think looks interesting.
Second, you should add your decorative lighting. I suggest adding decorative lighting, because it can affect your overall light levels and ambient lighting should always be added last. If there is a chandelier you'd like to use or a particularly attractive lamp, this should be added next. This lighting should be placed in such a way that your visitor's eyes can focus on the decorative lighting, without creating glare.
Finally, you should add your ambient lighting. This should light the rest of your room to about a third of the level of your task and accent lighting. However, be sure to make your room bright enough. In general, if your room is too dark with 1/3 accent lighting, your task and accent lighting are probably too dim. This layer of lighting prevents your room from becoming too cave-like, while still allowing you to have a variety of lighting levels in the room. Using layering is the first step to lighting any room, and is done by adding different types of light sources, one after the other.