The cleaner and more inviting you home feels to potential buyers the better you house is going to show.  Light some candles before showings, or keep a pot of water with some cinnamon sticks and cloves on the stove and let it boil for a few minutes before showings.  Try NOT to use arousal cans.  Some people are allergic to them, and many times gives the impression that you're trying to cover up some other odors.

Open all the widows and blinds.  Letting light in will give you house a warmer and more welcoming feeling.  It will also make the house to appear larger and more open.  Turn on all lights before showings when possible, even during the day.  Leaving lights on will give your house a more homey and inviting felling at night

If you have pets, ideally you should take them with you when you know someone is coming.  That way people are able to look with out distractions, and you don't have to worry about the cat or dog getting out.  You of course won't be ale to take the animals every time you have a showing, so be sure to mention it to your agent when listing, and they can make a note of it on the Multiple Listing Service so other agents are aware of your pets before they get to the house.