One thing I picked up is like a thin, close fitting ski mask that just has an opening for the eyes, and nose if
you want to pull the bottom of the opening down a little. Only thing it could be a little longer. But when it
gets really cold and windy, that really is nice to keep the face warm behind the face shield, and is thin enuf
material so it's not uncomfortable even in my snug fitting helmet. I'll post a photo of it here in a few days or
so - gotta dig it out for winter pretty soon.
One other thing I just thought of this morning while riding to work (1230AM, temps dipping into the 30's)
was a welder's "sleeves" that are made out of leather and are basically two sleeves with just enough
connecting them shoulder to shoulder to keep them on. Sort of like a jacket with most of the body cut
away below about shirt pocket level on the front, and very little material on a person's back. Just one layer
of leather, not bulky or thick or anything, but the leather should be an effective wind barrier over a jacket
or whatever. They're made for welders working in hot weather to protect them from sparks falling down
on their upper body and arms.

There are different types, some with nothing more than the sleeves themselves, and some with a shorter
"body" section than in the picture - no longer than about where the emblem is on the chest on those,
but you get the idea.
That hit me when I noticed just enuf wind coming around the upper corners of the windshield and hitting
me right on the shoulders and very upper arms, a cold enuf spot so it got my attention.
Not that it would work for everyone on all bikes with all different types of windshields, but I think I'm
going to see if I can find a set at a welding supply store or online, or even flea bay.