Benevolent psychological warfare was practised by Saladin, but was enhanced by greater and greater action heroes / hackers throughout the ages: including Sesame Street, The Beatles, web 2.0 bloggers / online writers and online entertainers, My Little Pony: Friendship is Magic, and YouTube videos.
The good news is that it is easy to practice, and can even be applied by people who are not in a position of power. And it can be summarised by the famous adages "Be excellent to each other" and "Don't be a dick." (= Wheaton's Law).
If you interact with a fellow person, shake his hand. Expect everyone to improve and become better (= the Pygmalion effect as opposed to the Golem effect) and act accordingly.
Thank someone for doing something you like. But be honest and tell someone if you dislike some action he took, or one of their works/creations (even if you feel they are your superior).
Express interest in the other person. Ask them "What's up?", "What's new?", etc. If he says "nothing much" tell them they should try to be less boring than that.
I recall that during the 2018 FIFA World Cup Final, the Croatian president, who is a woman, was so sweet and hugged all the (male) players of both teams: her native country, Croatia — and France — which won the match.
Similarly, Queen Elizabeth II has reportedly recently actually attended a wedding to which a British couple invited her as a joke.[comedy-is-serious]
Sometimes people may refuse to interact with you, in that case say: “OK, no problem, have a nice day!”.
It is also a good idea to compliment your friends and acquaintances, of whatever sex, for their looks. I recall telling a gorgeous young woman who came to visit one of the fellow patients in the hospital: “You are beautiful”, and she thanked me for that, and noted that nobody had told her that in several years. (Which made me sad.)
One important thing to note is that we all have our limitations and we are not good at everything. As a result, it is important that we sometimes ask other people for help, despite whatever Feudalism-like take on “independence” there may be. For example, I prefer not to cook complex meals myself, because cooking and learning to cook would be a grand waste of time for me and I'd produce mediocre at best results.
For some additional inspiration, you may wish to listen to the Beatles' songs "Help!" and "With a Little Help from My Friends".