To get practice, you can’t just sit and scratch your chin. You have to make a predction, write it down, then see how real life played out a few years down the road. It helps to write down predictions you considered but rejected and why.
the idea that sustained practice till you become fluent in the use of specific mental models is missing in much of the literature.
Just like learning any other skillset, using mental models effectively takes a lot of work.
This is often the missing key to effective use. It is one thing to read about a mental model (say Donella Meadows's systems thinking), and be able to recall the material from memory and quote it and so on. It is quite another to be able to apply that model (here systems thinking) to real life situations and get useful results.
I know many people who can quote chapter and verse of literature about mental models, but their thinking remains confused and ad hoc when it comes to dealing with real life problems.
To practice, one can also apply mental models to case studies/situations from the past and compare to the outcome predicted by the model and the actual outcome.(To be fair, there is a risk of making mental models fit the known outcome here, so one has to be aware of that)
EDIT: (not the same as mental models, but since someone mentioned ARIZ/TRIZ above) Edward De Bono's "Serious Creativity" and "Lateral Thinking for Management" (yes terrible title) are full of thinking tools that can be practiced systematically. Most of his books are repetitive and have varying ratios of fluff to core material, but these two together have most of his useful ideas.
There are people out there who have done all that work for you. All you have to do is pick up a book, learn their models, then stand on their shoulders as you develop your own.
It maybe less efficient, but in my experience, practice has consistently been the most effective way to learn something.
If you're looking for efficient, then you'd want a well-structured mix of theory and practice.
> All you have to do is pick up a book, learn their models, then stand on their shoulders as you develop your own.
Rarely does this work for any complex topic. I can't imagine learning math, or languages, or coding by simply picking up books. IMO, these models are very similar -- they have a ton of depth that can't be internalized without practice.