You can also make switches when liberating cities, too. Switch the tiles over before you click "liberate" will grant your cities the tiles. Good when you're liberating city-states since they do nothing after liberation.Yeah, it's a pretty good trick if you're not planning on expanding your empire further. You can pillage all their tiles and districts, capture the city and swap any land you desire to your own, and then negotiate peace with even greater yields. The other benefit is because you're returning the city you're not getting as many warmonger penalties.