I try to read old books. “None of us can fully escape [the blindness of our age], but we shall certainly increase it, and weaken our guard against it, if we read only modern books.”
I don’t trust the Establishment’s “experts” automatically (including the scientific and medical “experts”—”it is as easy to tell lies in scientific language as in literary language”). But I also don’t automatically believe the opposite of what the Establishment says. (“Experts” often lie, but non-“experts” are often unreliable.) I try to distrust and verify.
I try to beware the man of one study. A single study proves nothing; anyone can link to a study justifying pretty much any view. (Related.)
It’s irresponsible to have political opinions if you haven’t done your homework and thought through the best arguments on both sides. If you’re not willing to do that—and 99% of people aren’t—you shouldn’t have political opinions. If you are willing to do that, this list of books and this list of articles can point you in the right direction. (Don’t feel guilty if you’re not willing to put in the work to think through the best arguments on both sides. You probably have much better things to do with your time than think about politics.)