Check and/or add new weather-stripping to doors.
Clear out weep holes in window sills so water will drain efficiently
Test furnace and replace new filters
Have your fireplace cleaned and inspected.
Replace batteries in existing smoke and carbon monoxide detectors.
(Consider replacing with the new tamper-proof detectors offering a 10-year-lifespan battery.
Clear/clean out clothes dryer ducts.
Adjust irrigation sprinklers for less time and fewer days after rains have begun.
Change timers for outdoor lighting.
Inspect roof and clear out rain gutters.
Wrap pipes and faucet susceptible to freezing.
Apply winterizing fertilizer to lawn.
Prune trees, rake leaves and mulch.