Maximizing money for stable provinces as WRE

How do you build for provinces that are stable and on the back lines? E.g. Britian especially late game as Greco-roman pagan.

Right now they generally are Circus, Aqueduct, Estate, Statue and fishing port or wine emporium. The two towns have cattle pen and sheep flock or farm depending on if they're infertile or not. I struggle with the last building. Usually the resource if it has one, or a thermae to deal with sanitation. I have had a couple where I could put local industry. Sometimes I have to put the religious statue since it doesn't have any negative effects.

I tend to have some problem dealing with the local industry and the +10 order and squalor penalty. I know I could probably just build it to level 3 or something, but that really annoys me.

Anyway, I have a 3000 food surplus, so I know now I'm probably overdoing the agricultural part. I have a few provinces that just run at negative food no matter what e.g. Sahara, since it's hard to stabilize without a temple.