Check your weather-stripping around windows and doors for leaks or cracked glass to keep the warm in and the cold out, you may need to replace some weather-stripping or even do some caulking.
Check around the house for overgrown branches and trim them back from the house and electrical wires to prevent iced-over or wind-swept branches from causing property damage or a power problem.
Be certain rain or snow drains away from the house to avoid foundation problems. The dirt grade — around the exterior of your home — should slope away from the house. Add extra dirt to low areas, as necessary.
Clean and dry and cover patio furniture.
Bring your seasonal tools inside and spray them with a coating of lightweight oil to prevent rust.
Weatherize your lawn mower by cleaning off mud, leaves, grass, and debris.
Check fireplace to see if it needs to be cleaned before you use it again. Also, check the flue for drafts.
Clean or replace the air filter in your furnace for maximum efficiency and improved indoor air quality.
Check that smoke alarms and carbon monoxide detectors are in working order.
If you have an older thermostat, replace it with a programmable unit to save on heating costs.
Make sure fans are switched to the reverse or clockwise position, which will blow warm air down to the floor for enhanced energy efficiency and comfort.
Clean gutters of any debris.
Ensure all vents and openings are covered to prevent insects, birds, and rodents from getting inside to nest in a warm place.