For those pissing about with candles or torches, you're wasting your time and effort. A 4W LED bulb could light up a room all year without even switching it off for £11. If it's just used when you're in the room and when it's dark the annual cost would be less than £2. The cost of lighting a whole house shouldn't be much more than a tenner a year.
If you want to save money, turn the heating down a bit, take showers instead of baths and don't leave the TV on when you're not watching it, and if you have any old tungsten bulbs replace them with LEDs.