Paint the walls a brighter color. Choose colors that enhance your decorating style to make this change work with the furniture you have in the room. It isn't necessary to paint the walls white; a light color such as butter yellow or a light apricot will brighten up the space as well.
Cover your dark couch or chairs with light-colored blankets or furniture covers. The blanket option works best if you've decorated in a country or eclectic style. Use handmade cotton quilts for this purpose. Otherwise, find some cotton or linen couch or chair covers on sale.
Place an arrangement of candles that you purchased from a dollar store along with some decorative candle holders or a candelabra in your fireplace. Add cheap candles to the wall sconces or make a candle display on the dining room table.
Hang up mirrors. Mirrors and other reflective surfaces reflect the light that's already in the room, making the room look brighter. Hang a mirror next to a floor lamp or wall sconce to reflect the light that these items give off. Position a mirror on a wall near a window to help reflect the natural light that comes in.
Look for lamps at secondhand stores, yard sales and flea markets. Buy several different types such as floor lamps, clip on lamps and lamps for your side or coffee table.
Hang up lighter curtains. Buy cotton or linen curtains at the end of the summer going into fall; these items will be on sale then. Choose light-colored curtains. Or hang a window scarf on the window, which covers only the top portion of the window. Add a set of inexpensive shutters to the lower portion of the window under the window scarf. The design of the shutters will allow you to let in light and provide you with some additional coverage for the window.
Paint your wooden furniture a brighter color. Add some decorative stenciling to dress it up a bit.
Avoid putting too many pieces of furniture in a room. Too many items in a room makes it look crowded and dark.