The best way to remove a stain from a wood floor that is nongreasy, such as nail polish or food, is to use warm water and dish detergent. The solution is used with a soft cloth and rubbed onto the stain.
A greasy stain is removed from a wood floor by mixing ammonia with cold water then applying it to the stain with a soft cloth. A white ring stain is best removed from a wood floor by placing a soft cloth onto the stain and rubbing a hot steamless iron over it for a couple of seconds. Alternatively, a very fine steel wool pad with lemon oil on it can be rubbed onto the stain.