What you have to look at is:
Insulation. An un-insulted home is a nightmare to keep warm. We have hard flooring so I have draught excluders at the doors, loft hatches sometimes get forgotten, I lined the curtains with fleece and thermal curtain liners.
The efficiency of the boiler.
Personal habits, mil drives me bonkers leaving all the doors open and then complaining she's cold. I wear thermal long sleeved tops and long johns because they stop me feeling the cold too much. She heats the whole house but mainly stays in three rooms all day. We turn all the lights off, we run the machines on the cycles that cost least, I don't use the quickwash facilities on the washer or the dishwasher. It's little savings that add up.
If you have a hot water tank check the thermostat on it, ours was set to 75c but I moved it to 60c. Any more is a waste of electric, plus I only run the water for 20mins to heat a tank. I ordered tap and shower inserts off my water board, they are free from a lot of them but they stop you wasting water.
The billing structure, if you don't have a standing charge you usually pay more per unit for the first 600 units, 1m square of gas on my meter is 10 kwh of gas. 33p on my bill but on mil bill that would be 85p, it's the same with electric. Primary units can be 23p but secondary are charged at 11p.