For an interesting perspective on this topic I recommend this post at Ribbonfarm on "The Calculus of Grit".
Whatever you pick, I recommend also getting good at writing, in particular at explaining clearly and succinctly things that are relatively non-trivial and counter-intuitive. It's rare and valuable in itself; it also eases the job of persuading others that you do rare and valuable things.
Not an answer to your question, but I recently realized that all skills supplied by the standard curriculum of modern education were by definition oversupplied and therefore nearly worthless. "Study anything that other people don't" is probably not a bad heuristic.
Custom furniture-making, custom boatbuilding. Starting successful technology startups. Running the front-end of a fancy restaurant. Being some sort of "personal consultant."
The rare skills and knowledge that are directly applicable to your own life through being a human. Medicine, fitness, sex, motivation, rationality. The more money you have, the more you can farm things out, but you're still left with the problem of judging which farmer to employ, which requires some knowledge on your part.
Basic public speaking skills are always valuable, even at the lower level, but the ability to speak really well is rare and valuable. The same principle applies to writing well -- it shouldn't be as rare a skill as it is, but it's always worth improving.
A good knowledge of accounting and taxes tends to be useful in a lot of areas.
For most people, knowledge of how to cook won't directly be part of your career, but these days, it's a valuable social skill, maybe especially for males. As Robert Rodriguez has said, you gotta eat the rest of your life, you might as well know how.
I'm reminded of Heinlein:
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
Personally, I've never planned an invasion, and I'm not going to start now. Also, changing diapers is a lot easier with modern disposables. Hardly a skill at all.
I'm reminded of Heinlein:
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
Pfft. I wholeheartedly reject Heinlien's thesis. Comparative advantage and fungibility are awesome. He can go change diapers, pitch manure, take orders and die. Doing those things sucks.
I'm going to respectfully disagree with you specifically about the taking orders part.
In Heinlein's day, until Vietnam and the eventual end of the draft, many, many young males had military experience. The ability to take orders and give orders was assumed, and the ability to do so skillfully was recognized and admired. In the days of big, hierarchical organizations, this was the path to career success.
However, big, hierarchical organizations haven't disappeared. There are also a lot of relatively small hierarchical organizations. But the ability to give and take orders is not as common as it used to be. It was always valuable, but now it's also rare.
"Dying gallantly" is part of the same thing. I'd suspect that Heinlein knew perfectly well that dying as such isn't a skill. I interpreted him to mean that the willingness to take severe risks or blows on the part of your team, and perhaps more importantly, your subordinates, is hard to fake and is admired.
ETA. I still would not put my manure-pitching or hog-slaughtering skills on a resume.
Don't get me wrong, I am totally in favor of other people taking orders. That's just not my comparative advantage when it comes to utilon maximization.
Doesn't that assume that you're always the most expert person in any situation you're in? If the firefighter says, "Get out of the building now", what are you maximizing by being a leader instead of a follower?
Not on your resume, perhaps. But if we go through a global disaster, you may yet be glad you have them, if you do.
Hey everyone I just read this, which in turn lead me to this and I'm curious as to what are some skills and fields of study that people think fit the category of 'rare and valuable'.
Not just in white collar environments either, but also considering the entertainment industry, hospitality, trades and so forth.
I've noticed anything that involves interfacing tends to have good dividends, especially if you can freelance.
Would love to hear your thoughts.