Have a look around the main site here too for stuff.
http://www.selfsufficientish.com/budget.htm- budget food. In fact lots of the recipes are for cheap food. Do you have freezer space? pauls burgers are cheap to make and you can freeze loads
http://www.selfsufficientish.com/paulsburgers.htm
mind you it seems like you have already got it covered when it comes to living cheaply with food. How come you spend so little, what do you eat?
If I am sensible about money I will sit down and work out exactly what I am spending it on. Well actually my girlfriend will sit down and work out where money is going. Giving up smoking has saved me a fortune, bit that is another story. Then you rationalise where the money goes. Make sure Tv is not on stand by, computer not on constantly, light off, less cups of tea if toom much goes on electricity.
Use a pressure cooker to bring down the cost of cooking (gas) by using one ring to do a whole dinner.
If you get really fed up with sitting inside being cold then on a dry night why not sit in the garden and have a bonfire, you could also do you cooking on it. As a boy I used to find doing that exciting. Once more it is free heating/cooking/lighting for the evening. Just a thought thinking off the top of my head here.