A good mattress is an expensive investment, so it makes sense to learn how to take care of it. Unfortunately, spills or accidents occasionally happen, especially if you're having breakfast in bed or your children aren't yet potty trained. But, how do you clean a mattress? After all, it's not like you can just toss it in the washer if it becomes soiled.

The best thing you can do is to avoid getting your mattress dirty in the first place. Encasing the mattress and the box spring in hypoallergenic cases protects them from dust and grime and will cut down on dust mites. However, liquid can still seep through most cases and into the mattress. You may want to consider placing a rubber sheet on the mattress for protection against spills or childhood accidents.

Of course, since most people find that these rubber sheets bunch up and are uncomfortable to sleep on, you may prefer to risk getting the mattress wet, especially if there isn't a big chance that you will spill your morning coffee or your children are older. If you do get your mattress dirty, you can follow these simple steps to get it clean.

1. To remove dirt or dust, whip out your vacuum. Most mattress manufacturers suggest that occasionally vacuuming your mattress is a good idea, even if it doesn't look dirty, to keep dust mites under control.

2. If you need to clean up a liquid spill or a stain, don't grab your favorite stain removal product. Mattresses are made of materials that may not react well to chemicals. Instead, you should just try to blot up any liquid and leave the stain alone. If you can't bear the thought of leaving the stain on your mattress or if it has a strong odor, you can use a cloth dampened with cold water to gently scrub the stain. You can use a bit of mild soap on the cloth if the stain won't budge, but just be sure you don't end up making your mattress or box spring wetter than it already is.

3. Once you clean up the spill or stain, leave the sheets off your mattress and let it thoroughly air dry before you cover it back up. There's nothing worse than a moldy mattress, especially if the person sleeping on it has severe mold allergies.

Once your mattress is clean and dry, you may want to use this opportunity to flip it over so that it wears more evenly. You should flip your mattress over three or four times a year to help it last longer.