The best way to wash windows is with a squeegee. This method is the quickest, prevents streaks and is ecologically friendly. If a squeegee is not available, a sponge makes a good alternative.
For a cleaning solution, there are several recipes designed from ingredients found around the house. Common dish soap mixed with warm water makes a quick solution that helps cut through dirt and grease on windows. This formula is useful for interior windows. Mix 1 teaspoon of liquid dish-washing soap for every gallon of warm water. Too much soap can cause streaking, so remember that less is more.
If windows are more heavily soiled, a mixture of ammonia and vinegar makes a cleaning solution that breaks apart the dirt and helps prevent streaking. Add 1/2 cup ammonia and 2 cups rubbing alcohol to 8 cups of warm water. Stir in 1 tablespoon of dish-washing liquid to help give this cleaning solution added grease-cutting strength. Use this indoors or outdoors.
For outdoor windows, a cleaning solution made of water, vinegar and lemon essential oil cleans windows and doesn't leave any streaks. This mixture also helps prevent frost from building up on windows. To make this solution, use 1 cup of water, 3 cups of vinegar and 10 drops of any lemon essential oil. Put the cleaner in a spray bottle and use it liberally on windows.