Easy Money
Quick gold via the stockpile trick.
Easy money in Stronghold Legends.
At the start of a scenario you can build a stockpile for free. After building the required granary, delete the stockpile for gold, then build another one for free, and repeat for quick money. Use it to raise buildings early: set up a market and buy the raw materials you need for buildings and units. Note: materials in the stockpile disappear if you delete the building, so take advantage of pausing the game.