Cohoon recommends a vinegar-based cleanser, which won't damage hardware or stain curtain or drapes. Likewise, if you're going the store-bought route, try to avoid glass cleaners that are ammonia or is alcohol-based, as these may leave streaks or light films that attract more dust down the road.
Odd though it might seem, wiping down glass with newspaper not only helps produce streak-free glass, but also a lovely, bright shine! Be sure to spray your cleaning product on the newspaper or cloth rather than directly on the mirror. This will prevent the cleaner from dripping into the frame and possibly corroding it.
Professional window cleaners use a solution made from dish soap and water to achieve a streak-free clean. The key is to use a small amount of soap and distilled water. Some professionals add ammonia to the water for increased cleaning power.
Mix up your window-cleaning solution: In a plastic spray bottle, mix together 2 cups of warm water with 1/4 cup white vinegar and 1/2 teaspoon of Dawn. Sweep away dirt: Using a broom, sweep away the cobwebs and debris from the windows and sills.
Spray a stronger mix of 1:1 water and vinegar (or Windex, or glass cleaner) at your window, so that the solution covers most of the glass. (I found Windex to work better, but if you have pets—or kids—who frequently lick outdoor windows, vinegar may be the best route for you.)
You can also make an all-natural window cleaning solution using a mixture of equal parts white vinegar and hot water. Adding a touch of liquid soap to the vinegar solution will help remove any streak-causing wax left on the window from commercial cleaners used in the past.
A big problem is the evaporation rate. If you're cleaning your windows on a warm sunny day, the liquid part of the solution evaporates quickly and leaves behind a residue that appears as streaks. On the other hand, if you don't entirely remove the liquid you can also be left with a streaky window.
Dish Soap and Water
Dish soap is perfect for cleaning windows with residue and buildup, and you only need a few drops of dish soap to get the job done. If you're cleaning inside windows, use a spray bottle and if you're washing exterior windows, use a bucket.
The blue solution in the reservoir is an alcohol-based glass cleaner probably diluted with some water. After multiple people have wiped bugs, mud, oil, and gasoline off their vehicle using the squeegee and dunked it back into the tub, that fluid is more filth than detergent.
Instead of using standard cleaning products, get a bucket of water and mix it with dishwashing detergent or vinegar. Apply this cleaning solution to the glass using a long window scrubber. Grab a squeegee and pull its blade over the glass in a reverse “S” pattern.
Mix one part distilled vinegar to 10 parts warm water in a spray bottle. Wipe down the window with a a soft, clean, lint-free microfiber cloth or paper towel to remove dust before you spray your solution, then spray the entire surface.
Window cleaning professionals suggest avoiding window washing on very sunny days or at a time when a window is in direct sunlight, as the heat may cause the glass to dry too quickly and cause smears.
This has to do with the evaporation rate—if your cleaning solution evaporates before you have time to wipe it off, it will leave a mark. Alcohol- and ammonia-based cleaners evaporate more quickly than vinegar, but any window cleaner can leave streaks if it isn't removed fast enough.
“Vinegar is a good cleaner because it's acidic, but when you add dishwashing liquid/dish soap to it (which is a base or neutral) - you neutralise the vinegar. You take away the very thing that makes it work well. “The dishwashing liquid works that well on its own. Adding the vinegar is a pointless step.”
For most windows, combine equal parts distilled water and white vinegar. In most cases, it's best to do this in a spray bottle, but for larger windows combine more liquid in a bucket. For very dirty windows, especially exterior windows, combine 2 cups of water, 1/4 cup of vinegar, and 1/2 tsp of dish detergent.
You should use straight vinegar. If your windows are really dirty, it's good to use an extra strength solution to wash them. Just warm 1 cup (240 mL) of white vinegar. It can be applied directly to the glass and it's best to use a spray bottle for this specific solution.
Paper towels are an easy go-to whenever you're cleaning glass. But, that right there is your problem. Paper towel is the number one culprit of leaving behind streaks and lint. Paper towels are typically treated for absorbency, which makes them ideal for spills, but awful for glass cleaning.
Whether you are out of name brand glass cleaner or you want to use a more natural cleaner, vinegar works wonders on windows. Try a 50/50 solution of vinegar and water for a streak-free clean. You can use a spray bottle or dip a rag in the solution, just like you would an ordinary cleaner.