Are you on a water meter? Collect water that you normally run-off when waiting for it to go hot. Flush the loo with it. Make sure the tap is turned off when scrubbing your teeth.
Put a half-brick in the toilet flush so it uses less water when you DO use it.
Use a plastic washing-up bowl in the kitchen sink.
Make sure you put a lid on pans in which you are boiling water on the stove – boils faster and saves on gas costs.
Install an efficient boiler and room thermostat(s).
Commute by bike and rail on a yearly rail ticket (massive discount).
Pick the supermarket bottom shelves when buying toiletries.
Pick supermarket own brands for medication (aspirin and the like).
If you’ve an empty parking space – rent it out.
Make up a coffee vacuum flask and take it to work instead of spending £3 a cup every day.
That’ll do for now…