I think of myself as having average intelligence. When I worked hard I could get As when I slack off I can sneak by, when I do average work I get average results.
This makes me perfect to answer because nothing comes easy to me but nothing is out of reach if I apply myself. I do alright because I’ve put in the effort and here’s how.
Evidence based thinking: (what is the evidence backing this conclusion and how trustworthy is it?) without this everything you believe is no better than fantasy.
Room to be wrong: what if my prior assumption is incorrect? Can I admit that and get better? Without this you can never improve. (Also if you can’t ever admit you’re wrong that’s essentially the definition of being an asshole)
Avoiding perspective /assumption lock: there are classic thinking problems like the one that spawned the term thinking outside the box (look it up and answer for your self how this might be assumption lock). The apocryphal Charley Munger effort to armor planes better in World War Two (it was actually someone else’s work and far less cut and dried but interesting), the actual Charley Munger effort to save the lives of pilots by inverting and solving (how do I save the most pilots? Invert that and it’s obvious, now invert again and you have a solution)
Then practice. Seek out thinking problems, read about solutions to thinking problems and see if you can find similarities in solutions, thinking traps to avoid.
Try out chess and see if it gets you thinking ahead or about what other people might do. (Most people in prison can’t draw a causal relationship between their actions and their situation, chess taught me to not be like that)
Read the classic book on systems thinking and see if it resonates with you
Talk to people who challenge you intellectually (people who can successfully convince you of something you didn’t think before). Socrates says the loser of the argument is the one who benefits most. Because he leaves with new ideas. The winner only gains satisfaction and that is worth far less than knowledge.
Immediately after this step, return to step one and check evidence closely, because making a convincing argument is not always correlated with correctness. A convincing argument on faulty evidence is worse than useless. (Look up what Socrates says about sophistry)
Keep in mind that there are many types of intelligence. Emotional intelligence, financial savvy, street smarts.
If you’re not trying at all in any of those areas you’re leaving money on the table.
My buddy has low school smarts, high financial intelligence. His financial management is 100x better than his rich friends. He’s not “smart” he just tries harder, follows best practices, vets advice carefully and does the work.
Go do the work
Lay out some areas you want to get better. Look up best practices, vet them, practice them.
You’re already on the right track. (Excuse me I gotta go do something that guy told me to do but I never got around to)