Bring in More Mirrors
One of the easiest ways to trick the eye into thinking there are more windows, and thus, more natural light, is to hang some mirrors. The best position, of course, is opposite a window to really capitalize on the light it reflects. Similarly, mirrored surfaces such as chrome or other polished metals can help double or triple the illumination in a room by bouncing light. Have a dark corner? Consider a metal bookshelf, bar or chest of drawers and place an accent light on it with several glass accessories.
Mirror with shelf,
$69.99 by IKEA
Be Strategic With Lamps
Think of your lamps as pockets of light. You don’t want one big fixture just casting light down in the center of the room. You actually want various levels of light. Overhead ambient lighting, slightly dimmer accent lighting (think small table lamps, floor lamps that point toward the ceiling and wall sconces) and then brighter task lighting (reading lamps near lounge chairs or desk lamps). Having multiple types of lighting will fill the room and illuminate it in a more nuanced and inviting way, giving the room a more natural, all-over glow.