Showing a home to prospective buyers when there is a dead squirrel floating in your pool is a definite no. You'd think that's obvious, but Saatchi says it happened to a client of hers who hadn't been outside in awhile and didn't spot the dead animal.

Many home sellers pay little attention to the outside of their houses, especially during the winter. But potential buyers look at your home's exterior "with very critical eyes," Da Silva says.

"Put some flowers out there, make your driveway look nice, and if the roof is dirty, clean it," she says.

Take the time to trim shrubs around the house, especially if they are blocking windows. Washing the windows is also a must.

"The house needs to show," Da Silva says. "If you are saying to the public 'look, come to my house,' you need to make it look the best."