For health purposes, it's recommended that bed sheets and pillowcases get changed once a week. More washing and drying means more wear and tear on your sheets, so ideally, you'll have at least two complete sets that you alternate each week. Your typical set of sheets in the 300-to-500 thread count range should be washed in hot water with regular detergent and then dried on a hot setting. This is especially important for allergy sufferers, because the hot temperatures help kill dust mites. But once you're up in the 1,000-thread count range, most of which are considered luxury sheets, the washing instructions are a little different. High thread count sheets use cotton threads that are thinner than regular yarns, so when they're exposed to high temperatures, they're much more likely to break. These sheets should be washed in warm water and dried in the dryer on a cool setting. If you prefer your sheets to be wrinkle free, then you're probably going to have to do a little ironing.
When washing sheets, it's important not to overload your machine because the rinse cycle won't be able to get all of the soap residue off. Leftover soap means your sheets won't feel as soft. If you wash a full load, you may want to consider running an additional rinse cycle. It's important not to use chlorine bleach or detergents with brighteners on your bed linens because they can weaken the fibers. If you want to naturally brighten white sheets, just add a quarter cup of lemon juice to your load. If you use powder detergent, be sure to dissolve it in the water before adding your sheets to the mix. And try not to wash sheets with towels.