Close the windows. If you can, rely on an air conditioner during pollen season. The AC can also help you stop indoor mold and mite growth if the indoor humidity level stays below 40%. To monitor how much moisture is in the air, consider getting a hygrometer (sold at hardware stores, starting at $5).
Banish dust. When shopping for new furnishings, choose leather, wood, metal, or plastic, which can be cleaned with an electrostatic fabric duster, a wand that removes more than 90% of dust mite allergens. Consider covering upholstered couches and chairs with washable, removable slipcovers.
Vacuum often. The floors, carpets and any upholstered furniture should be vacuumed twice a week. If possible, use a cyclonic machine (like a Dyson) or one equipped with a micro-pore or high-efficiency particulate air (HEPA) filter, which reduces the particulate and allergen count in a room.
Hide your stuff. Avoid organizational tools, such as straw baskets, that collect dust. Instead, stash books, magazines, and DVDs in closed cabinets or sealed plastic containers.