The simplest (and cheapest) option, by far, is to use a polycarbonate mirror with a hydrophilic coating added, which encourages water to form a very fine film rather than droplets and fog. As a result, we believe these are the finest fog-free shower mirrors. They also look great! A word of warning: Although most hydrophobic coatings are transparent or have only a few color variations, there are some rare cases where they are not; if you get one that looks dark or colored, don't use it in the shower.
There are two types of mirror coatings: those that require an additional layer of glass on the back (usually for aesthetic purposes), and those that can be used as a single-surface mirror. Single-surface mirrors are more durable and resistant to scratches, but they cannot be used when looking into the reflection because there would be no way to see your image.
It is important to note that although most hydrophobic coatings are self-cleaning, some are not. If you get one that has stains or marks on it from previous users, try to avoid using the shower until they can be cleaned off. The best way to clean a mirror is with a soft, dry cloth; do not use soap or abrasives because they will damage the surface.
Finally, make sure that you maintain your mirror at least every other time you wash your hair.
So, what should you use to protect your mirror from fogging up? Shampoo. Yes, regular shampoo or shaving cream will suffice in the short term. Apply some to a paper towel just before showering and clean your mirror, or at least the patch you need clear, and then wipe dry. The chemicals in shampoo are anti-fogging.
Shampoo also helps remove any residue that may have built up on your mirror over time, which can affect its clarity.
If you don't want to use shampoo, there are other ways to keep your mirror clear. For example, if you spray it with water and let it air-dry, the moisture will prevent fogging by keeping the surface smooth. You can also use non-shampoo anti-fog products like those made by Uniroyal. These products are available at automotive parts stores and auto-parts chains such as Sears and Pep Boys.
You should always test a new product on an inconspicuous area of the glass first to make sure there are no allergies involved. If it doesn't cause any problems, go ahead and use it everywhere!
Now that you know how to keep your mirror from fogging up, you should do so every time you wash your hair. This will help maintain maximum visibility while driving.
All you have to do is smear some soap on the mirror while you're bathing. I use bar soap and just lather it up on the mirror before rinsing it off with my hand, leaving only a little residue. The mirror will not become fogged up. Just remember to rinse the mirror afterward to keep buildup to a minimal.
If you want to take your mirror game to the next level, there are several products available for purchase that contain anti-fog additives. One such product is called "Foam Off" and it can be found in most auto parts stores. It's made of petroleum jelly and works by preventing moisture from reaching the surface of the mirror. While this does prevent fogging, it isn't recommended for mirrors that require washing because the wash will remove any foam anti-fog additive.
Another option is to buy a separate anti-fog coating. These can be applied through a spray paint or lacquer and will protect your mirror from fogging up due to heat or moisture. When applying a coat or two, make sure to let each layer dry completely before adding another one so that fog doesn't return when you reapply the film.
The last option is to buy a new anti-fog mirror. These are available for most car models and generally cost less than $100. They work by using microscopic bubbles that reflect light away from the mirror's surface.