Back in the day when I was still wet behind the ears, my first winter in France resulted in a whacking great EDF bill. (It happens when you turn electric heaters on in September and turn them off in March...)
After the pain incurred in paying that off over a two year period (it was that big!), I've been careful ever since.
Even so, the bills are still always larger than I would like. Anyone got any good energy saving tips they would like to share?