Air conditioners, fans, and heaters are typically the biggest energy consumers and the biggest opportunities to decrease our energy usage. Make sure that you are not running the AC or heater when you are not home. Heat or cool only the room you are in rather than the whole house or building. Get a smart thermostat that helps you auto set temperature based on occupancy. Set your temperature levels at the minimum levels you can stand. Every degree helps save energy. If the room is cooler, put on a sweatshirt instead of turning up the heater. Open your windows to get your room cooler rather than use the AC.