The larger the size of each tile, the bigger it will make the room appear. Since fewer tiles are needed to cover the floor, there are fewer grout lines. The eye is drawn to lines in floors as well as in wall and ceiling coverings and upholstery patterns. Fewer lines provide a better overall visual perception of oneness and continuity. However, tiles that are cut to fit the space impair the effect, so choose a size that allows full tiles to extend across the room.
Simple tiles with little or no patterns in them also make the room appear larger. Choose straightforward designs with plain or simple geometric finishes and lay them in a diagonal pattern from corner to corner to make the room look bigger.
The belief that light colored floors make rooms look bigger than they are is not always true. This trick only works if the walls are in direct contrast with the floor, so if you have a white floor, paint the walls a dark color or alternatively choose dark tile and paint the walls white.
Natural light from large windows or skylights creates an aura of openness, as do torchiere-style lamps that bounce light from the ceiling to the floor and walls and recessed light fixtures that draw attention to different areas of the room.
Keep the furniture at a minimum and the decorating scheme simple and free of cluttering accessories such as overstuffed bookshelves and curio cases, throw pillows, wall hangings and plants. Small rooms with white ceilings appear larger than ones with dark colored ones that make the room feel short and constrictive. Glass tables and stands give the room an open feeling and mirrors or mirrored tiles create a feeling of depth in a small room through reflecting light and colors. Keep the colors and styles in the room visually balanced as a large, brightly colored focal point like a sofa overwhelm the space and make it appear smaller.