[G&K] Beginner help: economy on Prince

I got Civ V and G&K for Christmas, and after a couple early and disastrous forays into the middle difficulties, I decided to get my bearings on warlord and browsing the forums. I have my bearings now, but moving up to Prince there's one thing that frustrates me every game: money. I'm consistently at a deficit in the early game and it ends up eating everything I get from city states and selling resources. I recover in the medieval period if I'm running tall, but I haven't found any solution for wider empires and it still handicaps me in the early going. I think my biggest new expense are the spearmen and archers needed to protect against rushes, but I'm not certain.

Anyway, any general advice on controlling expenditures or getting money early would be greatly appreciated. I am not pleased to be running a deficit on normal mode.