Turn down the temperature to your water heater.
Turn off lights in rooms when you leave them.
Turn down the heat to the house, slightly but not too much, when you leave.
Use ceiling fans in the summer. Figure out which way is best for them to rotate.
Keep your air filters clean.
Leave clothes in the washer for a little while before drying them, so that any excess water can just drip off rather than having to be dried by the drier.
Don’t feel you have to wash all of your clothes so often either. Some clothes need it after every wearing, but consider some that might not. Keep the house cooler at night, and use another blanket or cover. Consider how to more efficiently take a shower, so that you aren’t in there quite as long.