Use subdued colors in large areas and bright colors in small areas. Accent neutral background colors with small areas of bright color. A focal point is whatever draws your eye when you first enter a room. Emphasize only one area rather than making many areas compete for attention. Lines should provide variety without confusion.
Lines can provide direction or movement of the eye throughout a room.
Shape and size. Use a variety of shapes for interest. Make sure your furnishings are in pleasing proportion to one another and to the room. Different textures lend different feelings to a room. Use patterns to add interest.