Here’s a great article by Joe D’Agnese for This Old House Magazine:
“All that rubbing isn’t a good idea,” says Brent Weingard, owner of Expert Window Cleaners in New York City. “You’re just moving dirt around from one spot to another and putting a static charge on the glass, which attracts dust and dirt. As soon as you finish, the window looks dirty again.”
As Weingard demonstrates, it’s easier and more effective to clean glass like the pros do: with a squeegee and a few other readily available tools. The techniques aren’t complicated, he says, and the results may surprise you.
“I don’t know of anything that can transform living spaces so well. You don’t know what you’re missing until you do the windows,” says Weingard. Here are two 3-step methods; one for picture windows and another for multipane windows. Got stubborn spots? Step 7 will help you with those.