. To keep your bathroom mirrors from fogging up, apply a small amount of liquid soap to a dry washcloth and wipe over mirror. Take another washcloth and rub till no more soap is on the mirror. My husband loves this since he shaves after getting out of the shower.
Some sites also suggest using small amount of shaving cream for the same purpose
however in my opinion the best and easiest way to stop fogging mirrors is to keep some pieces of old newspapers or magazines in the bathroom with them you can do a quick cleaning of your bathroom mirrors after fogging, this will quickly clean your mirrors, make them shinny and you will avoid any wastage of soap or shaving foam
This is a very small and easy tip and will definitely stop the fogging of your bathroom mirrors whenever you take bath