1. Take photographs of the room with every light on and during the daylight, particularly when the sun is shining.  Have the light from the windows as exposed as possible.
  2. Take photographs from a low angle.
  3. Frame the symmetry in the room with your photographs.
  4. When showing the room, have all the lights on and the curtains wide open, with nothing obstructing the natural light.
  5. If possible have professional photographs taken.