Close Off Unused Rooms: Keeping doors closed won't just prevent cold air from moving into the rest of the house -- it will help contain the heat you've generated (whether it be from a fireplace, radiator, or elsewhere).
"There Are Many Unusual Ways To Keep Your Home Warm Without Turning Up The Heat."
Set Your Ceiling Fans To Rotate Clockwise: Whether you know it or not, your ceiling fan needs to be changed seasonally. By setting them clockwise in the winter at a lower speed, you can drive warm air down towards you and your guests.
Add Some Layers to Your Floor: Area rugs aren't just a way to add color and style -- they were invented for the practical reason of keeping your floors cozy. Floors account for as much as 10 percent of heat loss if they're not insulated, according to the National Energy Foundation, and rugs can be that missing insulation. They'll keep cool air from seeping up into the room, and your toes will definitely thank you.
Change Your Sheets: Again, sometimes simple is tremendously effective when it comes to keeping warm. Swap cotton for flannel sheets, grab a down comforter, and don't forget about the value of extra blankets.
Foil Away: Wasted heat means wasted money, but a little DIY can always save the day. Putting tin foil behind the radiators in your home reflects heat back into the room, rather than allowing it to escape through the walls. Though they do make foil specially designed for this purpose, the quality stuff in your kitchen will also do the trick.
Call a Professional: Making sure that your heater, boiler, or oil burner is running well by calling a professional HVAC technician. While it may cost a bit more upfront to have your unit repaired or replaced, it will save you money in the long run and will help ensure your home stays warm throughout the winter.