[mter]

Cut the elastic ear loops off of an old mask and tie it to the elastic on a new mask to bridge the gap between the new mask ear elastics (or use a piece of string) so the pressure is on the back of your head.

If you fly a lot, there are also very likely commercial solutions for this.

[MengerSponge]

A well-fitting elastomeric respirator is comfortable and much cheaper than n95s in the long run, but it will get more looks in public. If you're the kind of person who cares about that, just use 3m Auras.