Let the light in.
Paint neutral (earth tones), browns, greens, maybe blues...remember colors do affect people psychologically--stay away from reds! Yellow does subconsciously say "buy me"-- it might be better to put yellow outside in planted flowers...
Plan the furniture arrangement so there is ample space to walk around the pieces of furniture.
The curb appeal is key--cut the grass, plant someting that will bloom during the initial offering, new welcome mat, have the windows cleaned, powerwash and paint as needed.
Family photos are a no-no.
Buyers don't want to know that you actually use your bathroom either. Place all bathing supplies in a shower caddy and keep them under the bathroom sink.
No garbage in the house!