The best way of ensuring a sale is to ask a realistic price - a property doesn't have a fixed market value and is worth exactly what a buyer is willing to pay for it.
However, don't undervalue your home. If house prices are rising and property is in demand, you should test the market first before accepting an offer. If you have an unusual property that's in high demand, such as an exceptional period property or a converted mill or barn, it may pay off for you to invite sealed bids or to sell it at auction.
If your house is fairly standard for the area, find out its market value by comparing the prices of other similar homes on the market or those which have recently been sold.