What has worked for me: put the nose bit of the mask _high_ up on your nose, then do the usual thing of shaping the metal bit to your nose firmly, kind of try to shape the sides in just a bit, then put glasses on. You don't want to go too crazy, too squished if anything is worse than too loose.

It's basically a pain in the ass but it works for my particular face anyway. I can now, 9 times out of 10 fit it well enough that my glasses won't fog, and with n95, there's no evident leaks.