My "Bad Manager" experience was a true learning experience in my career.  He had his own philosophy on teaching us his management techniques.  Just a couple of tibits into his style -

He would regularly show up late 10 - 15 minutes late for meetings and then make us rehash everything we had been discussing for the previous 10 minutes.  When I thought this was just his way I found out he told someone this was a way to convey power.

Next, His advice to a coworker during a review was to speak over people and be cockier.  His belief was being cocky was the way to be promoted.

Also, he told a coworker who was having personnel life issues that he could be having back problems like another coworker.  The personnel issues were very serious and his words were not the calming influence one needs to hear.

And lastly, if he did "buy" a treat for the team he would get the day old doughnuts with the 50% off sticker.

I could go on and on but why bother.  He did teach me a valuable lesson.  Do not accept a bad manager who doesn't care about his people.