Staging
Clean feeling - Make your picture look pristine and feel clean. Your guest will want to stay at a place with this feeling. Fluff up the pillows and make the bedding wrinkle free.
Remove excess clutter - Remove garbage cans, power cords hanging down, and remotes to give the room a clean look. Take out policy pamphlets and marketing brochures.
Correct light bulbs - Have the same type or color of light bulbs (cold or warm) in your lamps and overhead lighting. Having the blinds open or closed for pictures depends on what's going on outside the room. If there's a construction site outside, don't have the blinds open.
Lighting
Time of Day
Exterior - Avoid shots done during the middle of the day. If the sun is straight up, it's going to give you harsh shadows on your building or property.
Some of you may have heard of the "golden hour:" the time right before the sun sets or right after the sun has come up in the morning. During golden hour, the light is going to have more red or orange hues that are softer. Though, you don't want to wait until that hour before you go out and figure out where you're going to take the pictures. Figure out how you're going to stage your furniture and lighting beforehand.
There's also something called the "blue hour;" similar to the golden hour, blue hour is that twilight time when the sun has already set or right before the sun has come up. This is going to give you blue tones in the sky.
Interior - These are the opposite to exterior shots. You want to take these during the middle of the day (from 11 a.m. to 3 p.m.). Don't take your shots at night because you're not going to get any natural light from outside. Without the natural light from outside, the picture will feel darker, and you might have to adjust your camera settings to compensate.
Weather conditions
Take pictures right after a rainstorm. The colors pop more and are vibrant after a storm. This mainly applies to when the clouds aren't dark, overcast clouds that are still there after the rain has stopped. Dark clouds will block out all the sun, and you want a light cloud cover for diffused sunlight.