For a long time, I’ve just put on DejaVu fonts and been done with it. Generally good enough Unicode coverage for me. But I know it’s been years since DejaVu’s been updated, and I wonder what’s very common today.
[As for the terminal, I’m guessing it’s usually still the standard fixed Unicode fonts?]
I use fantasque for my monospace, fira sans for my work horse ui font, and Garamond for my “someone wants to display serifs for some reason”