or swap in a straightened paper-clip for the shitty plastic strip most disposables have that doesn't hold shape.

Use pliers to straighten a clip and bend over the ends so it doesn't get stabby, cut a slit in an outer layer of the mask-strip-sleeve to slide out the plastic shit and slide in the metal. When shaped well it drastically reduces fogging.

This also illustrates what a shitty job most masks are doing at retaining aerosols, which are otherwise blowing out past your nose. Between the neck gaiters, bandanas, and badly fitted masks I see everywhere, I think most people's face coverings are nowhere near as effective as they could and should be.