1. Wipe the glass with a dry cloth after applying the glass with a bar of dry soap.

2. Wipe the glass with a cloth moistened with ethanol at 90 percent concentration.

3. Wipe the glass using a sponge or cotton cloth with a few drops of shampoo on it.

4. Apply glue to the glass in W-shape because the glue in W-shape can be distributed more evenly, before wiping the glass using a little water on it.

Any of the four methods can prevent fog from forming on the glass.