Step 1 - Find a nice bit of abandoned land no one holds title on.
Step 2 - Take picture of awesome bridge.
Step 3 - Photoshop bridge over picture of land.
Step 4 - Advertise said bridge over the internet, convince plebs bridge leads to promised land.
Step 5 -Take payment for land lacking above bridge, buy a real bridge.
Step 6 - ????
Step 7 - Profit.