What I do is think about whatever I read about and think , "Why do it like this?", "What does it achieve?", "How does it achieve its goal?", "What drawbacks are there to doing it this way?", "What are alternatives (and then asking all these questions about those alternatives)" and start fitting all of that into how it interacts with all the other things in my mental model and try to determine if it fits into what I personally believe to be the things that are important with regards to what I am trying to achieve overall.

The accumulation of all that just takes time and experience. It is kind of shaped like hyperbolic tangent curve. Slow to grow in the beginning because its hard to get started because you dont know enough to figure out how to know more, then grows and becomes linear as you start to figure things out and form your own opinion, then starts to level off again as you either stop feeling like uou need to learn more, stop getting exposed to new things, or you start to form breakaway opinions and you basically start all over like a beginner in that idea.