artaxerxes, You didn't say(or I missed it) what year you were in, I'm playing Seleukids V1.0 in 184 BC.

I have reasonable garrisons, 3 very strong balanced armies(each with armoured Nellies) and 5 top tier fleets(9,000 each per turn).

35% of the map is mine, and my profit is about 50,000 per turn after all expenses paid out.

It's not just getting good port cities in trading groups, or the mines, but grooming Governers in top schools, swopping retinues etc. This can easily double a top cities income, partic places like Pella, Athens etc.

PS don't forget to keep trade roads clear of rebels. Pella went up from 10,800 to 11,800 once I removed the rebels off the trade road.