these are good tips. but wonder building isnt exactly easy. the ai doesnt even have to beeline to get in a good wonder. what ill do is get a merchant, change my specialists, trade resources, and build money buildings
One thing that isn't very clear is how much gold per turn units cost to maintain. Yes, military units like Warriors and Knights have gold upkeep per turn, but civilian units also have gold upkeep per turn.
This means that it is disadvantageous to have a huge surplus of inactive workers, because it costs a LOT to keep them around.
It also means it is disadvantageous to keep a LOT of Great People around. Most Great People won't be around for that long...except for Great Generals and Great Admirals. If you have five or so Great People hanging around that aren't supporting your military, you might want to consider disbanding a few.
However, my primary means to increasing my gold per turn is through war.
Conquering an enemy city usually nets anywhere from 50-200+ gold.
Puppeting the cities I conquer increases my gold per turn, both from the actual gold the puppet cities generate and through trade route income. Better yet, puppet cities increase my culture per turn without increasing the cost of social policies.
Make sure to use Trading Post improvements on all workable tiles of a puppet city.
When I'm conquering another civ's cities, it is common for me to capture 1 worker per city. It doesn't take long for me to have more workers than I know what to do with. If you disband these workers in your own territory, you get a small amount of gold.
Finally, the closer for the Honor tree means that I get gold for each unit I kill, something that happens a LOT in wars.