remember the basics.
even just raising a channel eq a bit, raises gain.
so as bit said,
it's a constant correction.
fx's drives gain....
panning can drive gain, depending on your chosen 'pan laws'.......
ultimately, i think the best case scenario,
is where you've recorded your individual tracks with enough headroom,
that if you zero out all your individual tracks faders,
and your master and sub busses are at zero (unity),
then you mix is almost finished!