1) Keep the gas tank at least half full; this decreases the chance of moisture forming in the gas lines and possibly freezing.
2) Check the tire pressure, including the spare, as tires can lose pressure when temperatures drop. Consider special tires if snow and ice are a problem in your area.
3) Have the exhaust system checked for carbon monoxide leaks, which can be especially dangerous during cold weather driving when windows are closed.
4) If you’re not trying to defrost the windshield or warm the interior, modern cars are ready to be driven right away. Idling longer than 30 seconds in most cases is unnecessary for the sake of warming up the engine. The best way to warm up your car is to drive gently at the start.
5) Change to low-viscosity oil in winter as it will flow more easily between moving parts when it is cold. Drivers in sub-zero temperatures should drop their oil weight from 10-W30 to 5-W30 as thickened oil can make it hard to start the car.
6) Consider using cold weather washer fluid and special winter windshield blades if you live in a place with especially harsh winter conditions.