Belittling your employees.
Something I've been thinking about lately... you can't belittle your employees as a leader or manager. And there's two ways that can happen, both are equally damaging.
1) Privately. Belittling employees to their face and when you are alone with them.
2) Publicly. Belittling your employees in front of other employees. Whether it's behind their back to other employees or in front of other employees, the result is similar. Employees will begin to take sides and the victimized employee will be shamed, humiliated and drug through the dirt.
The thing that always comes to my mind when I witness this behavior: you're the boss. If you are dissatisfied with an employee's performance, do something about it. You are literally in a position to actually do something about it. Coworkers with said employee are not. There is no excuse or reason to engage in building up an army against YOUR employee. It makes zero sense. Are you in charge or not? If so, act like it. Talking down and belittling your own employee doesn't show you have some sort of dominance in the relationship. It pretty much just makes you look like an abusive person.
So the next time you need to talk to an employee, seriously, take ownership of the situation and move forward. Don't belittle the person and drag it out.