Which self-help fads actually work?

I suspect some self-help fads actually do work when preached by the charismatic individual who started them: e.g., Rev. Norman Vincent Peale preached the Power of Positive Thinking to 9-year-old Donald Trump. But they usually don't replicate well in hands of non-superstars.

How many self-improvement fads/cults continue to work?

Here's an example from sports: serious weightlifting was considered a weird fringe training technique in many sports when I was a kid: e.g., pitcher Nolan Ryan started lifting after the 1972 season, but it took him a half dozen years to find a teammate, Brian Downing, who would do it with him.

Ryan went on to throw his seventh no-hitter in 1991 at age 44. Sandy Koufax is in second all-time with four no hitters. (Downing went on to transform himself into a Clark Kent-lookalike slugger and have a much better career from age 28 through 41 than he had had in his youthful prime.)

So, weightlifting works. (It especially works when combined with Performance Enhancing Drugs, of course.)

Baseball players should have figured out that weightlifting works a long time earlier. The great shortstop Honus Wagner worked out with dumbbells in the offseason 120 years ago. He peaked at age 34 in 1908, about 7 years after most ballplayers.

After his shameful 1925 season, Babe Ruth hired a personal trainer for the off-seasons and tossed the medicine ball around with him, hitting 60 homers in 1927.

So the gold standard of a formerly weird self-improvement cult that now consistently works is weightlifting in training athletes. It never goes out of fashion.

Motivational techniques, in contrast, seem to cycle in and out of fashion, suggesting, what, a placebo effect?

What else might consistently work?

Maybe Stanislavski's Method Acting? Daniel Day-Lewis took it to hilarious new extremes — when playing an 18th Century backwoodsman, he wore deerskins and carried a musket for months — but it sure worked for him.

One technique I recall from Dale Carnegie that seems to consistently work is an idea he borrowed from Ben Franklin: to get people to like you, it's useful to do them a favor, but what really works is to get them to do you a favor.

Fraternities train their bros to walk up to people to say hello, say their own name, and repeat the other person's name while shaking their hand, then reuse the other person's name in the conversation, so that they remember it.

That works.

I hope Cognitive Behavioral Therapy works. It seems pretty reasonable. It's likely that Obama got CBT when he got depressed after his primary defeat in 2000, and, if he did, it worked for him.

There are probably a lot of good ideas that are now considered common-sense that would have seemed weird a few thousand years ago. E.g., as Julian Jaynes pointed out, Odysseus seems more relatable to us moderns than does Achilles.