If it's cold out side, it's always nice to have a warm fire going. Neatness makes a room appear larger. You may need to box up some of your things and put them away until the house is sold. The kitchen should be bright and attractive. Take all of your appliances off the counters and put them away.
Clean counters make the room appear larger.
Bathrooms are very important. It is a check point for most people. Make sure they are extremely clean. Repair leaking faucets. Keep nice fresh towels.