If in doubt, switch it off: it is never more efficient to leave appliances running when you are not using them. Make sure you switch everything off at the plug before you go out and before you go to bed.
Ensure your heating is switched off at night and when you are away from your home (except in sub-zero conditions) and save 500kg CO2e a year. Don’t heat rooms you don’t use, turn the radiator off and close the door. Smart thermostats can go even further, sometimes slicing up to 30% off your heating bill whilst keeping your home more comfortable.
Read your meters monthly to check how much fuel you are using, or see if your supplier can fit a smart meter. This kind of monitoring can save on your fuel bills and also up to 250kg CO2e a year, as you keep a closer eye on your energy use.
Find out if you have any unfilled cavity walls and (if yes) have them filled. This extra insulation can make a significant difference to the comfort of your home and save over 1 tonne of CO2e.