Cold corners will condensate. Using your furnace to heat and a fan to keep air moving should help. Running the A/C when it's warm enough will remove moisture from the air. We have at times run the furnace, let it warm to 78 or so and then turn the A/C on and cooled it back to 70. We have a humidstat so can see that the amount of moisture is being reduced by doing this. Other things we do -- wipe down the shower after use - put towels outside to dry. Don't leave dishes sitting in the sink filled with water. Reduce cooking that involved boiling things like pasta, rice or potatoes. We also use Damp Rid containers in small enclosed areas like under the dinette seats, closets, and under bed storage areas. They collect a surprising amount of water and need to be changed out every month or so. We also do not open windows or vents when it's cold - counter productive to trying to heat the place.
