• Train Farmers to increase your unit production.
• Level your Food Factories in the Civilian Facilities.
• Increase your Productivity. Early on you can only reach 100% Productivity, this acts as a 1.0 multiplier. But later on you can increase your Productivity beyond 100% by researching Entertainment, allowing you to go over 1.0 in the productivity multiplier. For every 0.5% happiness beyond the 100% cap, you get a 0.25% increase in the Productivity cap. For example: 100.5% happiness would allow for a Productivity of 100.25% resulting in a 1.0025 multiplier.