Patterned sofa cushions? Flip them over if the other side is solid. It makes
  a huge difference and will allow you to incorporate different accent
  colours / patterns.

  Have a combined living / dining room? Switch sides. If the dining room
  light fixture is suspended, change to a low profile model to illuminate the
  "new" living room side and then use wall sconces and table lanterns
  for dining.

  Switch lamps or lampshades, using others in the house. You may be
  pleasantly surprised with a burst of colour or shades that allow more light
  to shine through.

  Remove all artwork and re-group by theme for more impact.

  Remove your area rug, especially if it is too small. Your room will feel much
  bigger - guaranteed.

  Re-arrange the books and accessories on your bookshelf by colour. You may
  come up with an interesting zig-zag pattern.

  Minimize your accessories, opting for the larger pieces. Remember that "less
  is more" and keep only what you truly love.

  Above all, don't be afraid to experiment with different groupings of furniture,
  art or accessories.