When buying a new appliance such as a washing machine, freezer or cooker, make sure it is an 'A' rated one. Also check on the annual electricity consumption for the appliance you are buying - the differences between models can be significant.
Particularly with freezers and fridges, the cost of buying the appliance is small compared to the cost of electricity it will use during its lifetime.
Energy ratings and annual energy consumption figures should be provided where the appliance is displayed for sale. In showrooms this is usually a label on the front. Websites and catalogues should provide this information on the product description page.
Carefully consider what type of lighting you want in your home. Dozens of halogen downlighters might look good in kitchen showrooms, but they use huge amounts of electricity.
Fluorescent lighting doesn't have to mean a bare striplight on the ceiling. There are literally thousands of light fittings available - catalogues are available from lighting manufacturers.
Room lighting doesn't have to be ceiling or wall mounted. Socket outlets for floor standing lamps or table lamps can easily be wired to wall switches.
A few years ago, a major appliance manufacturer had a range of fridges which had a heater in the outer cabinet. This nonsensical combination was explained in the literature as being there to prevent condensation forming on the outside of the cabinet.
Apparently, the designer had put so little insulation in the casing that the outer surface also became cold, causing water vapour in the air to form droplets on the outside. Installing a heater certainly removed the condensation. It would have also made the energy rating Z, if such a thing existed.
Of course, the correct solution was to have better insulation. If you are unlucky enough to have one of these design disasters in your home, please consider replacing it with a new one.