Paint the walls a light or bright color. White, beige and pastel colors make a room seem larger and brighter. Light colors reflect light increasing its amplification. Use semi-gloss or high gloss paint. These paints have a sheen that reflects light.
Add one or more mirrors to the room. A floor-to-ceiling mirror or a wall mirror is a well-known optical illusion for enlarging the size of a room. Mirrors also reflect the light that is already in the room.
Wax the floors. High gloss wood floors also help to add to the light in the room. Wax hardwood floors to get a durable and shiny coat.
Add a fireplace to the room. While this is not an option for apartment dwellers, the glow of a fire adds light to a room and also warmth during the winter months.