Home areas to insulate start with the roof because it has the greatest heat loss. Heat rises through the ceiling. Most of you will find three to six inches of insulation between the ceiling joists in the attic. My advice is to add at least six more inches to what is up there. I added 12 inches to the attic of my last house and reduced heating bills $30 a month. My current home has 18 inches of insulation in the attic; it saves money on heating and cooling.
Use unfaced or blown-in insulation to add to existing insulation. Considering the work involved, purchase the best insulation with the highest R-value. I used a 3-prong cultivator as a long tool to help place the rolled fiberglass insulation and minimize the crawling around up there.
Once you are out of the attic check the caulking around the windows, doors and thresholds. Drafty windows can be the cause of an uncomfortable area in the house.
Do not caulk the bottom rail of the storm windows. Water must be allowed to drain out or the sill will rot.
Next project is at the furnace. Check and change or clean the air filter. A dirty filter will hinder airflow and reduce efficiency.
Then open up the humidifier and replace the media if need be. Check for mold or slime in the unit and clean it well. You can use an additive to keep bacteria and calcium from forming.
These chores are perfect for the old saying “If you can’t find the time to do it right, when will you find the time to do it over?”