This is the most effective sequence of issues to look at when checking Home energy, and utility use, although savings can be made on any issue...

1. Structure. What Building Shape & Materials are you using for best energy conservation?
2. Aspect. Which Direction is your home facing? How best to make use of the Sun & Shade with windows, eaves, verandas, or sun courts?
3. Insulation. Check what Ratings are needed for floors, walls, ceilings, even windows.
4. Windows, Doors, & Airsealing . Check these have the correct thermal and noise insulation and are draft free.
5. Lighting & Daylighting: Are you upgrading to LED globes, and utilising available natural light?
6. Space Heating & Cooling and Ventilation. With correct insulation in place climate control is very economical. Monitor healthy ventilation requirements.
7. Water Heating: Solar and heat pumps are the cheapest way to go. Ensure pipework is insulated.
8. Water Use, Landscaping, and Storage: Use mulching  and tank water on your property.
9. Appliances, Electronics, and Solar Energy. Quality products give the best efficiencies.
10. Home Automation, Full control of energy, resources, fun, and security in your home.