A candle is lit in addition to electric lights. Flashlights can be used to assist as well. A blessing is recited if the search is performed on the 14th, but not when an earlier search is performed for various reasons. Since according to some, a blessing in vain—a bracha levatala— occurs if no chametz was found in the house, there is a widespread custom to 'seed' the area to be searched. Prior to bedikas chametz, several pieces of chametz are hidden around the house. These pieces must be small and should be wrapped so that crumbs do not escape. Traditionally, a feather and a wooden spoon are used, and whenever a piece of chametz is found, the feather is used to sweep the piece of chametz into the wooden spoon, which is then used to place it in a bag. It is best to use a candle to illuminate the areas; however, it is perfectly acceptable to use a flashlight or other light source. In some traditions, searchers also carry a bell to announce the discovery of chametz. The custom of using a wood spoon and feather is actually mostly unknown to those that practice this custom. The reason for the candle, feather & spoon is as follows.
Candle - candles illuminate and hyper focus their light on areas such as cracks and crevices.
Feather - used throughout the year to egg the challah, and therefore burnt in the chametz.
Wooden spoon - wooden spoons cannot be kashered and therefore chamatzdig "wooden" spoons were burnt as well together with the chametz
It is for most very impractical following through with custom with above described tools. Every part of every room of the house where chametz may possibly be found must be searched using this process. Rooms where chametz is not normally brought need not be searched.
Earlier search
One who is leaving one's property prior to the night of the 14th, but is not selling the property is required to perform a search without a blessing.
Customs
It is customary to place 10 pieces of chametz for the search. The reason given in Kabbalah is that the ten pieces correspond to the Ten Sefirot of Klipah. Another reason is that the ten pieces correspond to the ten plagues.