“First thing one should do is invest in a window squeegee. This can be bought at any department or hardware store. Then buy a sponge. Reserve this sponge for washing windows only. Rinse this sponge after each window washing job.
When washing windows, I use about one-half cup of non-sudsing ammonia to a gallon of hot water. Dip sponge into this and wash the window, rinse and go over the window again to get any spots that you might have missed.
Next, use the squeegee, going across the window until the width of the window is wiped. Bring the squeegee down the side of the glass to finish. Use a rag to wipe the squeegee after each stroke. Then wipe the edge of the window with the rag to pick up any water drops.
Never wash the windows when the sun is shining on them as this will cause streaks and result in a very poor job.
Note: I tried this method. It’s fantastic. I didn’t have a squeegee so I took a windshield wiper from the car! Wonderful! I suggest that people save their old windshield wipers. They are great.”
~ 1962 Heloise’s Housekeeping Hints