Did you know that the simple act of lowering the thermostat for 8 hours at night can save you 1%-3% in energy for every degree you drop? Turning your thermostat from 72º to 65º for eight hours a day can save as much as 10% on your annual heating costs.
I used to live in a 50 year old house with more leaks than a sinking ship. One winter we had a surprise bill of $400 for our natural gas heat. After a number of ever increasing bills, I had had enough. After trying plastic on the windows and other seemingly useless measures that didn't make a dent, I took a chance and spent $100 on an electric mattress pad and programmed the thermostat to drop to 55º at night.
Just cutting 14º off our heating for 8 hours a day helped cut our bill so much that the blanket paid for itself within two months. Flash forward 5 years, I live in a properly insulated house and even with a more efficient home and heater, I'm still using the same electric mattress pad. However now I use it more because I'm conserving resources, than just as a way to save money.