Though highest spore counts occur in summer, some molds give off most of their spores as the months grow colder. This is a particular problem for homes in the woods or close to a body of water. Leaf raking and jumping in stacks of raked leaves is an added invitation for mold spores to enter your life. Since molds grow under humid conditions, dehumidifying damp areas will reduce the chance of regrowth. Electric dehumidifiers are good but you have to keep them clean, too.
Avoidance is where to start.
It's best to get rid of leaves, clipping and compost piles around the outside of your house. And be sure to do any repotting of plants outside. Wearing a mask during these activities is helpful. Inside your house, most likely places for mold are basements, closets and bathrooms, especially showers. An exhaust fan can be helpful while cooking on the range or showering in the bathroom.