Surround your CityVille store with enough decorations and high-level franchise headquarters to pay out 2000 gold and it will come out as a diamond! Cluster your tall franchise headquarters and your highest percentage-bonus decorations around the store that pays you the most coins. If you are lucky enough to get a neighbor to franchise you a Tower eats then you can put 1-square bonus items closest to the store and only use larger bonus items around the outside edge of the cluster. Keep trying to put decorations in the cluster until no more will fit. Keep moving large decorations out until their blue square bonus zones still touch the store but they make room for smaller decorations closer to the store.
Keep your stores near the decorations, or the diamonds will stop. The highest paying stores give the easiest diamond payouts: Tower Eats, Chic Boutique and Jewelry Store. The cinema pays diamonds at 180 percent bonus. I also got the wedding store and the handbag store to pay out in diamonds. Arranging decorations and franchise headquarters around stores is one of the main strategies to getting ahead in CityVille. The more your stores pay you, the fewer stores you need to supply.