Lately I've been learning / playing poker. It feels like the perfect vehicle for what you're describing. I'm still quite new to poker so don't expect any deep insights here. You learn a little bit of the math behind when to expect what card, and what card your opponent is or isn't likely to have. Then you do battle using rationality, mostly against your own emotions.
You get into these situations where you know what the "right" move is but your emotions are firing on all cylinders. All the logical fallacies you've read about over the years (loss aversion, hot hand fallacy, etc) are suddenly extremely compelling. Even knowing that they are fallacies intellectually, it can still be difficult to make the rational decision.
And so you practice. You make the rational choice over and over in order to build an edge over you opponents. You become the house.
Doing this sort of "practice" I've noticed it paying off in places in my daily life. I sometimes find myself thinking of hard ambiguous decisions in poker terms now.
One thing that makes poker, or other games different from real life is knowing if you actually made the right call or not.
In the old poker days you used to have to guess, or talk it over with your poker friends to try to figure out if you bet too much or too little on that hand you can't stop thinking about.
The most modern poker theories and practices are around game theory. Through statistical analysis, simulations, and some ML tooling you're now effectively able to ask what the right move was for any given situation and get an objectively right answer. So if you're willing to use / pay for that software you have objective answers to those questions now.
At the highest levels online players spend many hours practicing with gto trainers to cement the "right" moves for given situations.
A problem I've noticed about trying to apply some of the lessons from poker to real life is that you don't usually get that objective feedback.
In poker sometimes you make a bet and you win, but it turns out it was a very bad bet and you got lucky.
Other times you might make a very good bet 3 times in a row, and get unlucky all 3 times.
In poker you can go back and look to find that they were all the right decision using a GTO (Game Theory Optimized) training software. Real life, not so much.
That said, these types of avenues still feel valuable to me. I really do think poker has improved my rationality and decision making skills. But like poker itself, those improvements are at the edges.