Hang a mirror. Hang a mirror (or lean a large one against a wall) to toss light around your room and open it up.
Add metallics. Golds and silver accents will make any space sparkle. Think picture frames, fixtures, lamps and decorative items like vases or candle holders.
Freshen with flowers. A pop of floral can brighten a room, especially when that floral is fresh. Add a bouquet to a table for a bit of vibrancy.
Think yellow or white. While light colors may show dirt and grime, white and yellow accents can brighten an area, fast. Add white and yellow throw pillows, swap out the duvet on your bed, or hang a new set of curtains.
Declutter. Last, but not least, a clutter sweep will help brighten your space up. Stack books, toss old magazines, fold the laundry and nix the knick knacks, and your home will thank you for it.