Wash windows on a cloudy day, but not rainy day. This is the best time to vacuum the frames and sills. Cool, clear water is the choice of most professional window washers. If windows are very dirty you can add 2 to 3 tablespoons of vinegar per gallon of water. For drying windows, a wad of crumpled newspaper works just as expensive paper towels. Wear rubber gloves to keep your hands free of ink.
To remove spots rub the surface with rubbing alcohol.