All you need is:
- my homemade glass cleaner
- newspaper (NOT colored/glossy color flyers)
- elbow grease
- a step ladder (if you have tall windows)
Work from the top of the window down. Spray cleaner horizontally and wipe with crumpled newspaper. Allow to air dry.
For best results, clean both sides of the window. (Enlist a professional for the outsides of 2nd story windows!)
That's it! The reason newspaper trumps paper towels is that newspaper is fibrous enough to effectively clean the surface, but has a smoother finish which keeps it from leaving behind fuzzy fibers the way paper towel does. And it's tons cheaper (and far more educational) than paper towel!