I've been playing around with my mask pattern here in Japan, both to make it more comfy and to find ways to keep my glasses from fogging up.
The host lady at our current BnB was kind enough to give us some boughten masks to use while in Tokyo. What I'm noticing is that they have a thin piece of wire embedded in the top edge to allow it to be bent & conform to the bridge of the nose, like so ...
This allows for a closer fit, and virtually eliminates my glasses-fogging problem. They also have very soft elastic, which make them easier to wear around the ears.
The next set of fabric masks I make will incorporate these hacks (assuming I can find some thin wire.) Just thought I'd share!