Posting as someone whose next Birthday is the Biblical 'three score and ten' and therefore on all probablities will never ever again look for a job in the Industry, I am saddened to have to comment on what should be obvious and common knowlege!
Treat every pilot you meet with respect because you will come across the same ugly mugs again and again throughout your whole career. If you make a bad name for yourself people remember.
In short;
Don't ever bad mouth other pilots whilst you're on the way up the ladder, because one day you might find that one of them is the Chief Pilot of the mob you've just applied to! Or related to the Owner etc etc
Stay out of the gossip
As above!!
I once overheard an instance when an aspiring Pilot asked a Pilot who was working for a certain mob if they had a vacancy for a 'relief' Pilot. The working (Female) Pilot replied in the most appallingly sarcastic tones I have ever heard that she
was 'the relief Pilot' and '....if we need another one, we will call you....' She didn't ask for contact details!
I believe that the Company CP later heard of the conversation and was not impressed!