Instructions
Raise the taxes of your city. This can cause a large amount of backlash by the population if you increase the taxes too much, but a slight adjustment can place a much larger amount of coin in your city's reserve every month.
Connect two neighborhoods within the town to create "Neighborhood Deals." These deals let the two connected areas flourish and create dependencies on each other. The areas between the two neighborhoods will begin seeing more houses appear, which can be instrumental in expanding the houses in your richest districts. This lets you tax more houses without using any income to build the houses in the first place.
Destroy existing buildings for quick cash. If you are in a tight spot and need a lot of money quickly, you can destroy existing buildings. Doing so instantly refunds a portion of the building's cost back to your city's treasury. However, this can have severe limitations on your long-term economic success because you will more than likely need to rebuild the destroyed buildings at some point.