#1- Remove window screens and pull up your shades. This will allow more sun to come through the windows and naturally heat your home, and also make the room brighter. Close them at night to retain the heat.
#2- Change your furnace filter. As a home inspector in Northwest Indiana, I’ve seen many furnaces that have been extremely neglected, and changing the furnace filter is one of the simplest ways to save money and energy! Not only will this improve the air quality inside your home, it will make your furnace more efficient. Dirty filters decrease the air flow, and will cause your furnace to use more energy.