

So it's winter once again, fuel costs are high, the economy is crap and you're cold. Well you can't do much about the first two but you can make your house a little warmer and more economic by doing just a few minor things.
Examine the seals on doors and windows, they have a tendency to rip and let air in, if necessary replace them.
Check around the foundation of the house for small holes, sometimes utility installers drill a bigger hole than needed and they let in a lot of cold air. You can use expanding foam such as Great Stuff to seal these shut. If you have access to the basement or crawlspace it's fairly easy to see light coming through them.
Check your attic for insulation. A lot of times attics are poorly insulated or not insulated at all. You can get cellulose insulation at Home Depot or Lowes and they usually let you use a blower if you buy a minimum amount.
Change your furnace filter. If it's dirty your furnace has to work a lot harder for it to blow warm air through your house.
If you're not at home during the day, turn your thermostat way down. Does it really need to heat your house to 75 degrees while no one is there? Turn it down to 60 or something. A lot of thermostats are programmable these days, if yours isn't you can buy one for about $30 and it only has four low voltage wires to hook up. It's fairly easy.