There are a few very quick fixes that you can do.
I expect you already have switched to LED bulbs, it saves you money, but do remember to switch lights off. Try to replace all the lights. We hung on to the lightbulb in the cupboard under the stairs because it had been there since we had moved in over twelve years ago. Reluctantly it is now replaced.
Re-programme your central heating timer for the seasons, the modern timers are much easier to do. Don't automatically turn the heating up when you feel chilly, jumpers, cardigans and blankets are cosy. Set the temperature one degree lower you might not notice the difference.
Use the radiator thermostat if you have them to set the temperature for each room.
Make sure you have the correct thickness of loft insulation and sort out your draughty windows and doors. Door curtains, thermal linings and a sausage dog draught excluder might not be all the rage but will help until the problems can be addressed. You can also buy covers to go over airbricks which allow air to circulate but stop the draught.
Replace single glassed windows and old double glazing.
Avoid the tumble dryer. We have an outside line which we use for large items and we use Victorian pulley dryers in two rooms of the house you don't really notice the clothes on them in fact I think clothes dryers and clothes over radiators are unsightly. Being close to the ceiling they take advantage of the warmer air and clothes will be dry the next day.
When replacing household appliances try to buy the highest energy efficient you can afford. Plan to use the oven for cooking several dishes, use lids on saucepans. There are lots of ways to cut energy using different cooking techniques and appliances. See Kitchen Equipment and Food and Drink sections.
Leaving appliances on standby wastes so much power every year. Turning off will save you money too.
Look into Smart meters, thermostats and plugs.
Switch to a green energy supplier. Big Clean Switch list renewable tariffs.
Look at your local water supplier's website for ideas to save water and sometimes freebies to help save water. When I last checked South East Water they had shower and teeth timers, tap and shower aerators and regulators, silicon non leak sink plugs and cistern bags all given away for free to help save water.