“Be nice to people on the way up, because you may meet them on the way down.”
– Jimmy Durante
Be nice to everyone. No one is trying to piss you off on purpose. Everyone wants to do a good job, including the lowest guy on the totem pole. He's just like you. He wants to do well enough on this job that he gets another.
Word travels. Make an effort for the words said you to be at the least, very professional, and at best also a helluva fun time.