So once you've got a government, what can that government do? What does it regulate, and how is it, itself, regulated? Laws can be created for a lot of reasons, some good and some bad. Sometimes they protect a citizen's opportunity to do certain things, sometimes they present a block to those opportunities, and very often, they aren't applied equally and equitably across all of society. So when you're building a world: How does the law work? From creation to enforcement to justice (or the lack thereof), what are the mechanics, and who has the ability to access -- or manipulate -- them?
Laws also aren't the only way that a society regulates itself. Moral standards, taboos, and customs also have a sort of governing force, as well as their own systems of enforcement. How does that get entangled with the way your characters live their lives?