On small jobs, the FOH jockey's shooting for a reasonable mix during sound check, one that will get increasingly dialed in over the band's first couple songs. Fine-tuning the bass (and the space other instruments leave for it) usually happens then.
I always do sound in bad conditions. I don't know the room, I do know the gear, my personal console and compressors, often don't know the band.
I try to make each instrument sound good individually, touching it as little as possible.
Then I check the whole band and try to limit the damage. That's when pass and notch filters get some action.
I can do decent to good but I can't do great. This has to come from the band.
Basically I work for the audience, trying to sculpt something pleasant. The band's desires barely come into consideration, unless they sound works well from start in which case I may have time for refinement.
I've cut and pasted the "Jist" of each time I've taken my rig out to do Festivals or One Off shows. Usually, I get a quick Line Check and a very quick Sound Check and we're off to the races. I'll finesse the mix over the first couple of songs and the rest will be little touches here and there. Rarely ever do I get to actually build a mix from the ground up with a proper Sound Check. Just my .02 worth.