How to clean a mirror? How to prevent a mirror from fogging up?

Use liquid glass cleaner on a mirror’s surface. If it is badly soiled, wipe with a warm solution of tea, water, and detergent, or use 2 tablespoons of vinegar, ammonia, or denatured alcohol in 1 quart of water.

Do not allow any cleaner to touch the rear of the mirror; it can discolor the reflective backing.

To discourage fogging, trail a soapy finger a few times across the mirror, then shine with a cloth.

To disguise a worn spot in the reflective backing, tape a piece of tinfoil to the back.

Don’t remove it later; the backing may come with it.