Moisture and mold or mildew may hit where you list expect them, such as in a closet full of stored clothing. Damp conditions with little air flow are ideal for mold and mildew growth but not for storing your apparel. Remove closet moisture by dehumidifying or providing a source of ventilation to ensure your stored clothing stays dry at all times.
A closet with a tight-fitting door -- especially if it isn't opened frequently -- traps in moisture, especially during humid conditions. Open the closet door and run a dehumidifier or air conditioner near the open door. Replace a solid door with a louvered or vented door, or open the closet door and leave it open for several hours every week or so to encourage air flow within the closet. Turn on an incandescent light within the closet, if the closet has one, and leave it on for several hours to help warm and dry the air.
Clothing must be completely dry before placing it in the closet. Otherwise, the moisture may increase the chances of mold, mildew and musty odors in the closet. If storing the clothes in some sort of sealed container, ditch the plastic storage tubs and opt for breathable packaging such as an old pillowcase or a cotton sheet. This allows the apparel to air out and and breathe. Avoid placing dirty clothing in the closet, as proteins embedded in the fibers may encourage mold or mildew growth.