There are tips on the internet.
Basically, if it's a combination boiler turn down the flow rate, turn the water temperature down for both water and heating, draft-proof the house etc, and turn off rad valves in rooms you are not using.
Nothing massive, it's just prices are crazy and it's especially cold, but only till Sunday.
https://www.which.co.uk/reviews/cutt...EaAnXlEALw_wcB