Well, the reason the Vietnamese won was through mastery of the environment. They knew the jungles inside and out, and the American military didn't.

We the People need to get to know our cities well because, if something like a revolution actually happens soon, that's where most of the fucking fighting's going to be. Plus, these are cops we're dealing with. Setting up ambushes for them would be pretty easy. It's open fighting during something like, say, a protest that the cops have always held the advantage of, simply because they were willing to use crowd control tactics and take advantage of the lay of the land while protesters were unwilling to.

So, know thy streets, to start.