Agreed to all the previous comments about price, cleanliness, and staging.
A family member of mine sold their house about a year ago, and we were heavily involved in the process. I'll add a couple of thoughts from our experience:
--A good photographer can make a huge difference. The right angles, the right lenses, and the right bit of retouching made their modest rooms look spectacular.
--The RE market has changed from what it was 20 years ago. Buyers have already seen photos and know the price, so if they come for a showing, you're already on the short list. The showing needs to give them the nudge they need in order to make an offer. The house needs to show them 1) why it's perfect for the buyers, 2) why it's worth your asking price, and 3) why it's better than the competition.
--Crissy is right--it's hard for most people to see rooms for anything other than what you stage them as, and you want to avoid rooms being used for non-traditional purposes. In my relative's house, one of their bedrooms was used as a big closet/dressing room for all their kids, and they packed up the clothes and set it up as a nursery. In our house, the formal dining room is used as an office, and when the time comes to sell, we'll stage it as a formal dining room.
--Humans are emotional. Buying a home is driven in huge part by emotion, whether it be the feeling of space (high ceilings), nostalgia ("my parents had a room like this!"), claustrophobia (declutter!), or fashion (seriously, do the paint colors actually matter?). So you need to play to those emotions.