and if you want to build your confidence about the benifits of lubrication
with the absolute least about of effort...  try using silicon spray to
lubricate the rubber guide at the front edge of the window.  the guide that
the widow sits in when in the upright position.  in my case, lubricating
this part had more positive impact than applying the lithium grease in the
guides inside the door (but that did help me too).  roll down the window and
place a rag at the base of the guide, then lightly spray into the channel...
you want to avoid getting the silicon on the paint or the glass so use it
with the tube attachment and use it sparingly.