This is pure fantasy, but I'd like for all musicians to quit saying self congratulatory nonsense to one another on the gig, like "You sound great tonight", etc. When the band sounds good, everybody knows it, and nobody needs to say anything. Verbal communication should be kept to concise exchanges of crucial information such as, "You're too loud/soft in my mix." or "Isn't that your wife that just walked in? Yes, she's at the bar talking to your girlfriend." etc.