Use a dehumidifier
Run air conditioning
Ventilate bathrooms and kitchens
Use exhaust fans while cooking and showering
Fix leaks and plumbing issues
Seal gaps around windows and doors
Dry clothes outdoors or with a vented dryer
Avoid overwatering indoor plants
Cover pots while cooking
Keep indoor humidity between 30% and 50%
Open windows when outdoor air is drier
Clean gutters and improve drainage
Insulate cold surfaces to reduce condensation
Use moisture absorbers in small spaces
Remove standing water quickly