1) Unplug phone chargers when not in use
Research shows that in the average home, chargers left in the wall while not in use account for up to 15% of your energy bill. Using a powerstrip to disconnect electronics when they're not in use can help dramatically decrease your energy bill.
2) Put a plastic gallon of water in your freezer
When freezers are full, they work more efficiently. If you don't have them full putting a plastic gallon of water in there will help make sure it
3) Use fans with AC
Floor and ceiling fans use just a fraction of energy that AC does (just over the average draw for a standard lightbulb) but still make a big impact on air temperature and the effectiveness of AC. Using fans with your AC can make the AC up to 30% more cost efficient.
4) Add rugs to wood floors
Because rugs limit the transfer of heat they can help to reduce your energy bill by up to 10% in both the winter and the summer.
5) Use a microwave whenever you have the choice
Relative to other cooking methods the microwave is more than 2x as efficient in its energy use. Particularly, for reheating you will cut your energy bill in half vs. reheating in an over or stove top.
Bonus: Use a home battery to only collect energy from the grid when it's least expensive
Not all energy is created equal. During the daytime energy from your utility company is only a fraction of the cost of what it is during peak demand in the early evening. By storing up cheap energy during the day and using it at night, you get independence from your utility company and cost savings to boot.