There are many things that can be done, I'll start with a few I've done at home.
Energy saving light bulbs - less energy used than the old filament type bulbs.
Standby saver - a small remote which will turn off all the appliances which use the standby saver plugs. I use these to turn off all the electrical appliances in my living room, one switch to turn off the TV, DVD, PS3 etc. I hate that most appliances use loads of energy even when on standby.
Set your thermostat to 0, this way the heating will only be on when i decide to put it on.