1) Location: You can't get away from this one. If your house is located in a desirable area that is in demand, you will be able to get a higher price than you can for the same house in a less desirable area.
2) Condition: A house that has been better maintained and shows better will always sell for more than one that has had deferred (neglected) maintenance and needs work.
3) Desirable amenities: If a house has amenities that are currently popular in the marketplace, it will bring a higher price.
4) Calculate the price per square foot: The average price per square foot for homes in your neighborhood shouldn't be the sole determinant of the asking price for your home, but it can be a useful starting point. Keep in mind that various methodologies can be used to calculate square footage.
A formal written appraisal can be useful if you have unique property, if there hasn't been much activity in your area recently, if co-owners disagree about price, or if there is any other circumstance that makes it difficult to put a value on your home. Appraisers consider the location of the home, its proximity to desirable schools and other public facilities, the size of the lot, the size and condition of the home itself and recent sales prices of comparable properties, among other factors.