If I get your question, then it depends. You can set it and forget it. Heck, you could pull all the knobs off and leave it that way. Or you can tweak according to each song you play. Or something in between.

In this, it depends greatly on what you play and what kind of player you are. Generally speaking, when I jam, the only thing I adjust during the evening mostly is mids on the amp. I guess in that sense my guitar (at least) is the most static (except the occasional roll off on volume to adjust overdrive). I hardly see why I need knobs on that at all :D

As you can tell, I'm not a major tweaker. If it sounds good, it's good enough!