Fifth, if you have any known allergies, especially if it's something in your bedroom, try to
either remove it
or or lessen your exposure to it
example, many people are allergic to dust or molds, and if you have carpeting, or an area rug, it can harbor these allergens. Frequently washing your bed sheets in very hot water also helps. Investing in a quality HEPA filter should help even more. If you have any pets, consider keeping them out of your bedroom.