Not MTB, but I commute on a 1x10 road bike. 48x12/26, never using the 26. That might be a little tall for a MTB depending on your area and fitness.

My previous cross bike had a double, but I never, not once, shifted to the small ring. so it was a 1x9 50x12/20something.

Thinking back, when I commuted on a MTB, I never shifted from the big ring, so whatever comes standard on a mountain triple was a good gear for me.