It also helps to make sure your initial city is on a river, for the commerce bonus to worked squares. It's cheesy to keep reloading for an optimum spot, I know, but I've found that if I don't start on a river, by the time my second settler is going out, I start losing money. As an adjunct to this, make sure you build roads on all worked squares, too. That's helpful both for unit movement as well as the commerce gained.
Aggressively selling your map can help a bit, civs will usually give 2 or 3 gold each for it. Also, seek out barbarian encampments, they give 25 gold when you clear them. Also be sure to sell your starting techs to other civs when you contact them. They may or may not give you a tech for it in return, but they should at least give you gold.
