Face masks. <sigh>
There are two basic types: the ones with filters which keep viruses from getting to you (N95) and the cloth/paper ones which keep you from aerosolizing a virus (or anything else you may have) onto others.
The second type (cloth/paper) will not protect you from COVID19. It will not. If you already have COVID19, then these masks will help to keep you from spreading it to others.
So, everyone should get the N95 type to protect themselves, right? Yes.
If there were enough of them. Which there aren't.
That's why they need to be reserved for healthcare workers. We all want the healthcare workers to be healthy in case we or a loved one gets sick, right? Given their shortage, no one should be using the N95s unless they have to provide essential services to someone who is infected. Not to go to the store.
Since the cloth/paper kind can prevent the spread of the disease since we *might* have it and not know it (thanks to a long incubation and mild to no symptoms), then we should all be wearing masks, right? Yes.
If there were enough of them. Which there aren't.
That's why, again, we need to reserve the cloth/paper masks to healthcare workers.
However, since people can make their own cloth/paper mask, then they should use that, right? Yes. Only if used properly. If you're constantly adjusting the mask, then you may be contaminating your hands and then whatever your hands touch. You should be cleaning the mask properly and putting them where they can't contaminate them until they're washed. You shouldn't let your mask become a soggy, drippy mess. So, yes, if you can make your own, or if supplies become abundant, wear a mask all the time if you know how to wear it properly.