People can keep their masks temporarily and have it reused later. Thus, make sure to remove your mask properly and clean your hands the moment you touch a secondly used mask. Store it in a very dry, breathable bag, like a paper or mesh fabric bag, to stay it clean between uses. If you are reusing your mask, ensure the identical side to face out.
If you're trying to remove your mask to eat or drink outside of your home, you'll put it somewhere safe to keep it clean, like your pocket, purse, or carrier bag. Be absolutely sure to clean or sanitize your hands once you've removed your mask. If you are done with it, then put the mask back on with the identical side facing out. Just take care to scrub or clean your hands again after you put your mask again.