For me, the most important thing one should think of when decorating a room is the color palette. If you are not sure you can think of your favorite color and then find the colors that best contrast it. This only applies if you have a colorful room in mind but other rooms can be more elegant using a grayscale palette with one color or no color at all. After you have your color palette, next is picking the furniture. But, this next step is much easier when you are following a color guide.