Nail the sale: Britt Skrivanek and Athena Gu

Skrivanek and Gu, like most sellers, based their asking price on what other homes in their neighborhood were listed for. Instead, they should ask their realtor for the going price on houses that are under contract or have sold in the past month or two.

"You have to look at what's actually selling, not what people are hoping to sell their homes for," says Denise Riordan, a vice president at realtor NRT. Then price the home lower than those recent sales so it looks like a great deal.

"You need a dramatic number to generate interest," says Riordan's partner, Jay Schweppe. Best-case scenario: The perception of value will attract multiple bids as buyers compete with one another, driving up the price.