Clearing snow or ice from a small circle of windshield glass maybe enough for you to see your way out of the driveway, but it isn’t adequate for safe driving. You can do a better, safer job with a little extra effort.
First, use a push broom to brush snow from the hood and the roof. Otherwise, snow will blow onto the windshield from the hood as you accelerate and from the roof when you brake.
Next, brush snow from the windshield, then scrape off any ice underneath. If the ice is thick, apply an aerosol spray, which typically contains the same alcohol used in antifreeze. Be careful not to spray it on the car body, for it may damage the paint (once diluted with water from the ice, the aerosol will not cause a problem if some dribbles onto the body).
Use a scraper to remove all traces of ice; the spray itself can cause moisture to evaporate, lowering its temperature and re-freezing it on the windshield. Clear side windows in the same way. Break ice from the windshield wiper blades and squeegees so that they can work properly. If winters in your area are severe, use special winter blades, which are encased in rubber to avoid clogging with ice.
Even if your car has a rear defogger, scrape ice from the rear window. The defogger cannot melt ice rapidly in cold weather. If you are driving at night, scrape ice from the headlamps and wipe them clean.
After 1 to 2 miles of driving, the engine coolant should be warm enough to provide heated air for the defroster. Turn on the defroster and use the windshield washer and the wipers to keep the windshield clean. Winter windshield washer solution, like the deicing aerosol spray, also contains alcohol (although a different type). Do not use the washer before the defroster can supply heated air, or freezing may result.