Did your teacher ever assign you to stay after school to pound the dust out of the blackboard erasers? For young children, getting assigned that task was an honor. For older ones, it was usually a punishment for misbehaving in class.
Now that you're an adult, one of those old-fashioned blackboard erasers may once again leave you proud as you look out through crystal-clear windows. After washing and drying your windows with either newspaper or coffee filters (see preceding hints), run a clean, dry blackboard eraser over the windows to remove any streaks and give them a diamond-bright shine.