Shoot plenty Coverage.
Yeah, the haters will say you're indecisive, you don't trust yourself, the actors will try to convince you that that last one totally nailed it and they cannot do better, or that doing something again everytime is eating up time or light or (least worth listening to) somebody's 'patience' or 'enthusiasm' ...
And too bad for them. They won't be sitting there WITH YOU looking at the million shots that all have to fit together like a puzzle ... and suddenly
that shot you only had one of, that somebody rushed or missed something, that needs to connect the chain of shots into a meaningful sequence, DOESN'T WORK (and there can be a dozen explanations of how something went wrong, but it DOESN'T WORK)
And YOU need to be able to say, or tell your editor "well, good thing I shot coverage THEN, because I just saved our asses NOW"
So shoot coverage,
whether it's the backup repeat of some necessary action,
or another angle that will cover up an error elsewhere,
or an insert close-up (the actress looked away there, do you need to see what she looked AT?)
or an alternate reading of a line ("No, THIS one." vs "No, this ONE.") or ...
well, COVERAGE.
It's right there in front of you. All you gotta do is capture it, one more time, as back up!
Camera One? Got it!
Camera Two? We're good!
Camera Three?
Ready when YOU are, CB! 
etc
I've been on little guerrilla crews where time was so desperate, corners were getting cut, a couple of people were rethinking how to do it or change it as light died or deadline approached ... and it's a nightmare.
SOMETHING
ALWAYS GOES WRONG. Forewarned is fore-armed.
Coverage is your best defense.