Unlock 10 Doughtnuts and Statue of Jebediah Springfield
Select Homer while playing to bring up his task menu. While the menu is open, click on Homer ten times. If done correctly a message prompt will appear stating you found the secret and will receive 10 doughnuts and the statue in your inventory.
Quick Collecting
When you have lots of buildings and people doing things, an easy thing to do for collecting your money and XP is to click on the thing on top of the building to make the money come out of the building and then do that to the rest of the buildings. You will notice that the money and XP automatically get deposited.
Plant Triffids
Triffids give you XP. They give you around 150 XP and eventually you have to do a quest to plant a receive them twice. Plant them unless you do not want to spend money to only receive XP.
Free Burning Bush Premuim Item!
Near the mountain area. There is a piece of land that has this item. Buy that land and place it anywhere. You can buy it for 20 doughnuts or have it for free.