There are numerous things lying around your home that are probably in need of a good wash. While most of us are good about washing our clothes and dishes on a semi-regular basis, many people forget to clean less obvious everyday items like makeup brushes, gloves, and fan vents as often as they should. Another item to add to your cleaning calendar? Pillows.

According to Apartment Therapy, you should throw your pillows in the washing machine twice a year, or more often if you live in a warm, humid climate. Doing so will not only cut down on the off-putting smells that result from months of nighttime drooling, but it will kill any dust mites that have gathered in there. (Dust mites thrive in tropical areas, which is why someone in Florida should wash their pillows once every few months or once per season, whereas someone in New Mexico doesn’t have to worry about doing it as often.)

Before you get out the laundry soap, make sure your pillows are worth washing. Goose down and feather pillows can last many years, but synthetic fibers don’t last as long. If the synthetic fibers in your pillow are clumping or have flattened out, that’s a good sign that it’s time to upgrade to a new pillow. To test your pillow’s viability, whether it’s down or synthetic, you should place it on a hard surface, fold it in half, and squish out the air. If it bounces back, it’s still got some life left, while a pillow that stays folded has reached the end of its life. (For more detailed instructions, the Pacific Coast Feather Company has a good primer.)

Now, you’re ready to wash. The best way to wash pillows is in a front-loading machine, because pillows can float to the top of a top-loading washer, where they don’t always get uniformly wet, Martha Stewart Living warns. You’ll want to check your pillow’s tag for the manufacturer’s instructions and make sure your pillow isn’t dry-clean only. If you cut off the tags long ago, don’t worry too much: As a rule of thumb, Good Housekeeping recommends washing in warm water on the gentle cycle with mild liquid detergent, then putting it through an extra rinse and spin cycle on cold to get out any remaining detergent. For feather pillows, though, you actually want to use powder detergent specifically designed for down because liquid soap can leave sticky residue.

To keep your synthetic pillows from getting mangled and clumped, Apartment Therapy recommends rolling them up like long sausages and securing the ends and middle with rubber bands. This will keep the material inside from sliding around too much. Try to wash two pillows at a time so that the washing machine stays balanced.

When it comes to drying pillows, the best method involves getting a little sporty: Unroll the pillow from its rubber bands and throw it in the dryer on moderate heat with tennis balls, which will help cut down on those clumps. If you add in a few dry towels, too, it will speed up the drying process. The automatic sensor on your dryer likely won't be able to tell that your pillows are still damp inside (since it measures exterior surface temperature) so you'll have to monitor the timing yourself.

If you use a memory foam pillow, however, you’re both lucky and unlucky. According to Consumer Reports, these can’t be washed or even steamed, and if you try to dry them, they’ll probably melt. On the one hand, you don’t have to wash your pillow. On the other hand, you can’t wash your pillow, so you should probably use a pillow cover to protect against your old sweat, oils, and grime.

[h/t Apartment Therapy]