Hey Mal, I used to work for a home builder. We had model homes for people to look at. One thing we learned was to use scents to give the house a homey smell. Of course these were new homes and I'm sure your home smells homely...definantly not saying your home stinks! Instead of leaving the house smelling of cleaning supplies, create comfort smells. We would burn potporri (sp) or pop popcorn, something yummy (apple pie) just out of the oven....in the "nursery" we made it smell like Baby Magic, in the winter we'd even decorate the house!
The main thing is set a scene...create atmosphere. I know they aren't buying the furniture, but if your showing your home in the evening, turn down the bed & have a nightgown drapped across the bed, a tub of bubble bath sparkling..........you get the idea.
Things like that really make a difference! It couldn't hurt!