Make friends with folks from authoritarian countries. An old co-worker of mine from Belarus told me that the most important skill to have under authoritarianism was learning how to bribe cops.
Authoritarianism is really just kleptocracy and cops have always been super corrupt. As everything gets harder because a small group is siphoning up everything while spending more than it makes, more and more cops will become more flexible with their enforcement of laws. They will randomly harass anyone they think they can get away with harassing in order to extract bribes, and they will ignore anything for the right amount. Learning to bribe under authoritarianism is far more important than following the rules... Because the rules don't actually protect you.
I never would have thought of this. I'm sure there are a lot of things like this I wouldn't think of.