Leave the door open if you can so that steam can leave the room. If you can't do that, open a window. If you are in a window-less bathroom, there should be an exhaust fan to help circulate the air and lessen the effect of steam build-up.

Leave the shower curtains or doors pulled back temporarily so that the walls can dry faster. Then pull the shower curtain closed to allow it to dry without being stuck together

Use a nonabrasive all-purpose cleaner or one that has a "disinfectant" or "antibacterial" label. But before you try any cleaner, read the instructions. Test it to make sure it will not discolor the surface you are cleaning.

Use curtains that are mildew-resistant.

Soap-scum remover will rid you of those ugly tub rings and other hard water deposits where mildew can start.

The area under your sick is prone to collecting moisture. Keep it dry and clean. Ditto for the floor in front of the tub or shower.

Launder your bath towels daily - or at least weekly. Hang them loosely so they can dry quickly.

Never put wall-to-wall carpeting in a bathroom. It collects and holds moisture. Even industrial carpeting is unwise. Should you ever have a spill or a toilet overflow, you'll be in trouble for sure.