The biggest problem still with a lot of the houses here in NH is they just do not have enough insulation in them. It is very evident just recently based on the amount of icicles hanging off their eves. Almost every house that was built prior to 1990 does not have enough insulation in its attic based on todays standards. Adding insulation to your attic will pay itself off within 3-4 years. Just going around and caulking around windows, doors and other openings will also pay off quickly. Lastly, taking off your exterior wall outlet/switch covers and foaming around the box will also air seal and save money. All of these things can be done easily by almost any home owner. There are also lots of videos now on UTUBE how to do all these things. They are not expensive and there is a tax deduction for insulation. However, it requires getting off the couch.