The Department of Energy estimates that a properly insulated attic can shave 10 to 50 percent off your heating bill. Sure, you can dial down the thermostat and get used to wearing bulky sweaters indoors to cut costs. But if you've got an unfinished attic, giving it proper insulation is one of the simplest ways to keep a lid on your heating bill this season. "It's a DIY project you can tackle in a weekend, and the savings you'll get add up every year," says general contractor