Your Yard can hold three Monster buildings. The Monster Locker is where various classes of monsters are unlocked and upgraded. The Hatchery is where you will convert Goo into monsters. Housing is where your created monsters will be stored and deployed for battles. Goo generators will become very important structures. Have two high level Goo generators and one high level building of each resource gatherer. Position them in the middle of the map and surround them by other buildings to distract attackers. Those other buildings should consist of low level resource gatherers, the Town Hall and all the other buildings you can currently create. Place walls and defense towers around the protected buildings.