I've managed a LOT of people over the years (not to mention taught martial arts for a couple of decades). To me, being a good people manager/motivator just isn't that hard:
- Help people prioritize their work and keep on task (with nudges as needed)
- Do a little blocking and bureaucratic bullshit so that they can focus on work. (Know what/how to delegate, and what not to).
- Keep a diverse/balanced team (intellectually), where folks compliment each-others weaknesses, and an environment where they're open to contributing differing views
- Play to people's strengths/interests, give them praise/recognition for what they do well (keep them happy, appreciated and motivated), and help them stretch (challenge them) at a rate that they can tolerate. (Give Credit, share the blame).
- Occasionally, play therapist and listen to their complaints. Sometimes doing nothing (just being a friendly ear for their frustrations), sometimes helping them back on track and focusing on what they can control or can do to make things better.
There's a lot of nuances of general management, like good communication, manage expectations, planning and other things as well. But for the wetware (people) side of it, it's mostly about the above to me.
Sometimes I'm amazed at how few "people managers" understand those requirements, or can do some or any of that well.
The easiest way to learn how to be a people manager, is think of why you left jobs. The most common reason to leave is poor management. So just use those managers as a "how not to". Learn from their mistakes. While there are other reasons I've left jobs (dying companies, no possibility for advancement, failed corporate culture), I made that list from remembering why I left because of bad management. Leaving out a few obvious examples like a boss that used to yell at people when they followed his directions into a disaster, or because he couldn't prioritize.
So I've seen all the examples of bad choices, occasionally in one place. Managers that put more demands on your time than you have (and berate you for failing to do everything they demand), and think that's motivating. The ones that push their bullshit work on to you, and wonder why that impacts performance. The ones that can only deal with one type of employee (usually beaten down sheep/followers). Or that rule by bullying and intimidation rather than motivation.