Purchase a plastic spray bottle. These can be found at most department and hardware stores.
Pour some rubbing alcohol into the spray bottle. Screw the cap on so it is ready for use.
Spray your windshield with the alcohol. The alcohol will quickly melt its way through the frost/snow and loosen the ice from the windshield.
Wipe the frost off as you normally would. The alcohol will allow you to immediately clear the snow off without digging with your scraper or having to turn the defrost on for 15 minutes first!