One way to save energy is to check your home's insulation. You want to protect it against air leaks and control moisture.
Check insulation in your attic, ceilings, exterior and basement walls, floors and crawl spaces to see if it meets the R-value in your area. The higher the rating the better. Use higher density insulation on exterior walls and in cathedral ceilings.
Check recessed light fixtures but don't put insulation right next to them as that might start a fire. Check to see if it is designed for direct insulation contact.
Ventilation helps moisture control, so be sure to have the attic vents installed. Check with your roofer to determine the type and amount of vents you need.
The cheapest way to insulate your home is to make sure you have enough insulation in your attic. Be sure to insulate the access door to the attic as well. Check with your local home improvement store for R ratings for your area.
Next find out if you need to add insulation to your basement, remember you don't have to insulate the entire basement.
More tips to come on finding out where Air Leaks may be found in your home.