Fed up with a foggy bathroom mirror? Then add some shaving cream. As odd as it sounds, using some cheap, white foaming shaving cream can keep your bathroom mirror from fogging while you shower.
For best results, use your hand or a soft cloth to rub a light layer of shaving cream onto your mirror. With a dry towel, wipe off any excess cream. Don't use water to do this, as it will cut down on the cream's efficacy. With some luck, this will help keep your mirror fog-free for at least a week.