Unfortunately, many cost-cutting tips for the home involve some kind of initial investment. Those that don’t cost anything would be to keep your thermostat at 68 or 70 at the most. You can let the house be a little cooler and compensate with a little more clothing. Another way to save on heating is to control your outlets. Most heating systems allow you to open and close the vents. Close the vents and close the doors in rooms that you will not be using. At night, you might want to close the vents in the living room and other rooms and just open the vents in your bedroom.
Turn the heater off whenever you are gone.
Beyond that, taking steps to better insulate your house will pay off in the long run. Gradually replace your windows with double pane glass if they aren’t already. Check your ceiling and wall insulation and replace it if needed. Normal wall insulation tends to sink to the bottom over time, leaving the area near the ceiling un-insulated.
There are small things you can do such lay a towel, or one of those long weenie things they sell, at the bottom of outside doors to prevent cold from creeping in. Also check the weather strips on your outside doors.
With a combination of tactics, you will be surprised how much money you can save on your heating costs.