Many people put off cleaning windows or struggle through it because they dont know what to use.  if you want crystal clear windows, Use the right tools and such as squeegees, a good amoniated cleaner and a good cloth. Never wash windows in direct sunlight because the sun can heat the glass and cause all sorts of streaking problems. 

Hold the squeegee at an angle so the water runs down the glass.  You don't want water coming from both ends of the squeegee. Wipe the blade after each squeegee stroke, You must wipe the  blade with a lint free cloth. Placing a wet squeegee on the glass will leave a blade mark.

For clear windows use ammoniated window cleaner. Then use a dry cloth and wipe one side of window with long motions  If there are any remaining streaks, the direction will determine which side of the glass needs to be wiped again.

HAPPY WINDOW CLEANING !!!!!!!!