Good managers are easy to spot. They say things like “Great job!” and “How are you doing?” all the time, because they know how to interact with their teammates and how to listen to them. They know that encouraging their teammates is the most important part of a manager’s job.
Lousy managers are a different story.
Some poorly-equipped managers will act friendly toward you one day and blast you the next. A poor manager’s behavior can be hard to predict.