The best way to create a spacious looking room, is to use light colors, including whites, creams, beiges, and pastels, and also using fabrics and surfaces that create reflection. It is not about cluttering the space you live in, it is more about organization. By using storage, it will help avoid filling a space, and create a more open aired room. Great fabrics that work well with natural light are like velvets, suede, satin, damask, matelasse, and plush fabrics.
When wanting to create light and space using paint you can do this by buying a paint that has a reflective finish. This usually means it contains tiny beads or spheres that when the light hits will give the wall an all over shine, and create a highlighted affect within the space. These reflective beads can also be found in highway signs, which creates that glow when headlights hit it.
However, this does not mean that EVERYTHING has to be white, a great pop of color, whether its an accent wall, or furniture accessories, will always give a great theme to a room, and can often show the house owners character.
To me a non-cluttered room gives the room more visual attraction and leaves a crisp and fresh feel. So keep in mind that you can always find use through space, furniture, accessories and means of storage to create your perfect 'clean' space.