Advice to new managers: don't joke about firing people

This is sound advice. You have a significant amount of control over people's lives as a manager, and that should be treated with a level of respect. You have no idea how people feel, and it is quite possible that someone you manage doesn't know where they stand with you. At times that is more than enough to cause them stress and even convince them to look elsewhere. Work is stressful enough, and you don't need to add to it…

That's excellent advice that many have learned the hard way... Honestly even as a non-manager it's a very bad idea. When I was a junior one of my colleagues was called to the manager's office. I assumed it would be for some mundane project scheduling or whatever, so I jokingly said "you're getting fired" as he was going there. And he was. This is one of these memories that come back to haunt you late at night when you're trying…

Likewise don’t joke about quitting as an employee with your manager, even if you both find it funny. It made it a bit more awkward when I actually really meant it.