Where the buck actually does stop!
The Director determines the mood of the set. If the Director is cheerful and having a good time, chances are everyone else will be, too. If the Director is being bitchy and fussy and demanding, everyone else gets that way, too. It’s a law of nature.
The converse appears to the true as well — if the set is a happy place, it’s probable that the Director’s in a good mood and if the set’s in a shitty mood, chances are the Director is, too.
If you are the Director, then make sure you’re in the right headspace before you walk on set, attend meetings, or anything that involves other people. Seethe and rant in your private journal or whatever, but once other people get involved, you’ve got to be chill and focus on getting the shots.
And thank you, Crystal, for this advice!