1. Wash windows on cloudy days for a dazzling shine. Bright sunlight dries out window cleaner too rapidly, causing streaks.
2. Professional window cleaners use clean water and a squeegee, drawing it across the glass and wiping off dirty water between strokes.
3. When you clean windows, wipe the inside panes in a side-to-side direction and the outside in an up-and-down direction. If you do this, you can step back and easily see which side the streak is on, so you won’t waste time recleaning the side that doesn’t need it – and running the risk of introducing new streaks.
4. If reaching the outside of your windows is difficult, shut them tight and spray them with a garden hose. Do it gently, just misting the panes – too much pressure could force water into the house or crack a pane.