Avoid streaks in your windows and other glasses
So you have cleaned your windows, then why aren’t they shining? Streaks or spots appear when the cleaning liquid that you have used dries up before you have completely wiped it. The trick in this case is to check the component of your cleaning solution whether it evaporates easily or not. If the major component, such as alcohol, dries up fast, chances are it would leave a mark. A good cleaning solution should allow you to have the time to wipe it before it evaporates.
You should also consider the weather when cleaning glasses since the weather also affects the evaporation of your cleaning solution. It is not advisable to clean them, especially your windows, when the weather is blistering hot.