What are some good things to do at home for decreasing asthma?

Dust mites. It depends whether your asthma is related to allergies. Specifically dust mite avoidance measures are important in asthmatics who are sensitized to dust mites. Obtaining dust mite proof pillow and mattress casings. Washing sheets and covers in hot water weekly, vacuuming with a hepa filter vacuum, cleaning ducts, and considering changing out carpet to hardwood floors.
Possible things... Take your medicines as prescribed by your doctor and avoid allergic triggers-these are the best things you can do at home to treat your asthma. Do not smoke and avoid second-hand smoke as much as possible. See your doctor or go to the nearest er if your symptoms worsen.