it depends on the type of window.
on plastic windows with good rubber seals i quickly scrub and rinse the top frame every time then straight onto the glass.
on wooden windows and windows with poorly fitted rubber seals i clean and rinse just under the top seal and dont touch the top frame unless its really dirty.then i go and clean another window and then come back and clean the glass only after a few mins.
if its ground floor windows that have dodgy top rubber seals then i go over top frame with a damp cloth and never wash and rinse right up to the seals.this keeps spotting down to a minimum.