It depends in what vicinity you live that determines a method.

Near a busy main road (where there is usually diesel fumes, dirty grime, etc) I used a dustpan broom to detergent wash, then rinse, then the old newspaper/metho way.  (But I think a different ink/paper is used nowadays and doesn't seem as good)

People in a seaside location probably have a method too.

In the normal neighbourhood situation, I use plain water to rinse off any grime.  Then a Vileda window cloth (or real chamois)  in clean warm water to wipe over for a streak free finish.  The more often they are done (bi monthly) the easier each time.

I do the interior kitchen window more often.  (And if it has steamed up or splashed by washing up, I wipe it over with the chamois immediately.)

I find  that some of the so called cleaners seem to attract dirt or leave a greasy film, that is why I use just plain water.

Oh and don't do it when the sun is shining on the glass.  

DEB