How the heck do you make money late game? (Without smithing)

I’ve conquered 12 imperial towns, most of Khuzait, fair bit of Sturgia, and all of Battania. I have 7 towns owned by my clan, all Empire. 3 have >6000 prosperity, though not by much.

How in the world do I start making money again? I fluctuate between -11k & -300ish daily gold change. The only way I can stay afloat is smithing cheese, which I’m a bit sick of doing tbh. I currently am about net even on tributes, I’d guess -200 or so total.

Am I missing something with town prosperity? My best town (Vostrum) is hard stuck around 6900 prosp, maxed buildings & a great governor. Is there a better way to do this?

I’d love to be able to bribe other lords to speed up the end game (have 4 clans now), but it’s tough without passively gaining gold.

Any help appreciated.