There is nothing worse then working with another DJ that is just a straight up 🍆! It doesn't matter if you are a opener or a headliner, don't be an ass. Being a dick won't make you a better dj or even get you booked.
As a dj you should encourage positive vibes and create a party that people want to comeback to.
If your opener goes in and opens wrong don't be a dick. Give them some positive feed back and then go on and kill the room. There is plenty of amazing music out there to kill a room. We were all once rookies in the game at one point or another. Show love to the rookies and they will show love back
For the headliners that think there the 💩 and think it's ok to be an ass, You will have ur time then u will be irrelevant. No one likes working with an ass and people will always remember that. So be humble and enjoy doing your thing.