10 Check the ductwork for leaks. You can pay someone else to do this, but it's not really that big of a job, as minor leaks can be repaired simply with metal backed tape available at most hardware stores.
11 Invest in a programmable thermostat. The U.S. Department of Energy suggests setting the temperature to 68 degrees while awake and at home, and 10-15 degrees cooler when asleep or away.
12 Have the furnace serviced and the filters changed. An inefficient furnace will cost you in added energy used, so it's worth the investment in a service call.