1) Insulate your home
Heating and air conditioning can make up a large part of your energy consumption and as much as 45% of your home's heating and cooling can be lost without roof and ceiling insulation. Installing insulation combined with appropriate ventilation can reduce your energy bills.
2) Install solar hot water
Hot water is typically responsible for about a quarter of a home's energy use. It can be much more if you have a large family that likes long showers or uses a spa bath regularly. Replacing electric hot water heating with a solar system can easily save half to three quarters of the energy you use for hot water.
3) Use a radiant heat lamp in the bathroom
Is your bathroom so cold you just want to stay in the shower? Install a radiant heat lamp to keep warm when you get out of the shower. It uses a tenth of the energy that you could lose by staying in the shower longer.
4) Update halogen downlights
Halogen downlights can use a great deal of energy for the light they produce. This is because they generate a lot of heat and not all their light spreads into the room. If you are buying halogen downlights look for the 35Watt IRC (infrared coating) units, which don't need as much energy to keep the lighting element hot. LED or compact fluorescent (CFL) down lights use even less energy but you may need an electrician to rewire your down lights.
Each person you add to a car increases fuel consumption by only a few percent, depending on the car's weight and engine size. If four people share a car, the fuel consumption could be as little as a third of the amount used if they all drove separate cars with similar petrol consumptions for the same journey.