Locate the creaking area of the floor. Usually this will be only one to two boards in a specific area.
Sprinkle powdered graphite or baby powder over the creaking area. The powder acts as a lubricant for the wood.
Walk over the squeaking area until the noise goes away. Walking around allows the powder to seep in between the loose boards.
Check to make sure there are no loose screws or nails. If you can see underneath the baseboards of the floor, try scanning the bottom of the baseboard with a flashlight to look for loose nails and screws.
Replace any loose nails or screws. If you find one underneath the baseboard that is loose, make sure its replacement is one to two sizes larger than the previous nail or screw.
Call a local repair person if the squeaking persists.