h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

for your bed, pinch the standard sheet quota from mum, then skoot off to the local market, and buy a few meters of fleace cloth.. use this as an extra blanket/sheet in the winter.. also does you proud when watching a film on the sofa and you need something to snuggle down under when the heating's gone off. They make nice throws too if you get the luminous green polar fleace too.

centeral heating, it costs a stupid ammount of money to raise the temperature of a room by a single degree, so just set it at about 18 or 20 and wear a jumper. If you don't believe me, ask an engineer who's done a thermodynamics module, and compare the energy to the cost per unit on your gas bill.

Radiators, these only work efficiently if there is backpressure in the system, ie, if a single radiator is fully on, all the water, and hence heat, goes to that radiator leaving the rest of the house bloody freezing. So only have radiators on by 2 turns, and turn them down if they are in a rarely used room (like the kitckn)