You know those bullet-point lists. You start spotting them everything at this time of year. They go like this:
How to Save Money on Energy Bills: Beginner Level
Don an extra jumper.
Insulate your loft.
Have a shower, not a bath.
Only boil as much water as you need in your kettle.
Put off turning on your central heating for as long as you can.
Turn the light off when you leave a room.
Unplug all your devices at the wall, because standby mode costs money.