1. It is forbidden to use a dry cloth to wipe dirty windows, otherwise the glass will be scratched and it will appear more dirty.

2. Do not clean the windows when exposed to sunlight, as the water evaporates quickly and smears will be left on the glass.

3. Change the water frequently when cleaning the windows, especially the detergent water.

4. Use detergent properly. Too much cleaner can leave a severe smear or residual layer on the glass. In addition, do not use soapy water to clean windows, soapy water is difficult to clean with clean water.