Ideally, windows should be washed twice a year, but it’s a task most people don’t look forward to. Part of what makes window washing such a chore is that homeowners insist on doing it with wadded-up paper towels or newspaper, spray cleaner, and a ton of elbow grease.

All that rubbing isn’t a good idea. 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.

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, 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. Here are two 3-step methods; one for picture windows and another for multipane windows. 

 
Step 1: Wash with a strip applicator

Picture windows call for large tools. The long cloth head of a strip applicator soaks up a lot of soapy water and knocks dirt loose without scratching the glass. For a cleaning solution, Weingard uses just a squirt of dishwashing liquid in a bucket of warm water—the less suds, the better.

 
Step 2: Wipe clean with a squeegee

Starting at the top left, pull the squeegee over the soapy pane in a reverse-S pattern (left-handers would start at the top right). At the end of each stroke, wipe the squeegee’s blade clean with a lint-free rag. Cloth diapers or old linen napkins are perfect for this task.

 
Step 3: Dry off remaining drips

Remove any water remaining on the edges of the glass with a damp, wrung-dry chamois, which soaks up wetness without leaving streaks. Dry the windowsill with a rag.

Step 4: Customize the squeegee

To clean a divided-light window, you need a squeegee that fits the panes. Use a hacksaw to cut one to size. He trims the metal channel ¼ inch narrower than the window pane, then files the cut edges smooth. With a utility knife, he cuts the rubber blade to the pane’s full width and fits it into the channel so that it projects 1/8 inch at each end.

Step 5: Scrub the panes

A handheld sponge or hog-bristle brush works best on multipane windows. Prefer natural sponges. They’re firmer and more absorbent than synthetics. Using the same solution of a squirt of liquid soap in water, rub each pane from left to right, top to bottom, working the sponge edges or brush bristles into the corners to loosen dirt.

Step 6: Wipe clean with a squeegee

Pull the squeegee down each pane in a single stroke from top to bottom. After each stroke, clean the blade with a rag so it doesn’t leave streaks. (If the squeegee squeaks a lot, add a bit more soap to the water.) As above, remove any streaks on the glass with a chamois, and dry the muntins and sill with a rag.

Step 7: Get rid of stubborn spots

Over time, hard-water runoff from masonry or rain falling through metal window screens leaves stubborn mineral stains on glass that normal washing can’t erase. So after a regular cleaning, wet the glass and gently “supercleans” it either with fine steel wool (if the panes are small) or with the cleansing powders Zud, which contain oxalic acid. (Other brands of powder may scratch the glass or fail to remove stains.) He mixes the powder into a paste on a wet towel, rubs away the stains, then rinses and squeegees the glass twice to remove the residue. Even with that treatment, the staining generally comes back in about six months.

For cleaning inside windows:

 
• Fill a bucket or large pot with clean, cool water and add a few drops of liquid dish soap.

• Place a large bath towel beneath the window to catch any spills.

• Use a clean microfiber cloth or sponge to go over the surface of the window, starting at the top and working down to the bottom. Don’t forget to wipe down the frame as well, both inside and out.

• Spray the window thoroughly with the vinegar and water solution, or if you prefer, a commercial window cleaning product (Zep or Windex work well). Another option is mixing one capful of ammonia with two gallons of water.

• Using a clean, lint-free towel (or the black-and-white pages of a newspaper), dry the window completely using a Z-shaped motion. You also can use clean paper towels to dry the windows, if you prefer.

• If dirt or streaks remain, spray and dry again. (Dirty windows typically require two rounds of spraying and drying.)

• It is best to work on a cool, cloudy day so that the soapy water and window-cleaning solution do not dry on your windows.

For cleaning outside windows:

 
• Outside windows typically have more dirt and stains. Start by rinsing the windows with the hose, then fill a bucket with clean, cool water and add a few drops of liquid dish soap.

• Using a soft microfiber cloth, go over the surface of the window. For higher windows, use a sponge mop (or a soft cotton or microfiber mop) on a pole.

• Rinse thoroughly with the hose.

• Spray or mop with the vinegar and water solution or with a commercial cleanser.

• Wipe the window dry using a clean, rubber-bladed squeegee. Angle the squeegee towards the bottom of the window and work from top to bottom. Wipe the squeegee with a clean, dry towel at the bottom of each pass. Alternatively, you can use a clean, lint-free towel or newspaper pages to dry the windows.

• For stubborn dirt and stains, including bird droppings, saturate thoroughly with vinegar and water and let stand for several minutes before drying. You can also try rubbing with a soft “scrubbie” sponge, but do not use steel wool or harsh scrubbing cloths; these will scratch the window.

• Don’t neglect the window screens. Rinse with plain water, spray with a vinegar and water solution, then rinse again with plain water. Let dry thoroughly before replacing the screens on the windows.