The two main things you can do are to control sources of moisture and increase ventilation. To decrease or control excess humidity and condensation:
Use exhaust fans in your kitchen, laundry, and bathrooms.
Vent gas burners, clothes dryers, etc. to the outdoors.
Shut off furnace humidifiers and other humidifying devices in your home.
Be sure that the ventilating louvers in your attic, basement or crawl spaces are open and amply sized.
Open fireplace dampers to allow an escape route for moisture-laden air.
Air out your house a few minutes each day.