Thanks both of you for feedback & ideas!
I was working on the background story for my Neerah char ("How Neerah the vengeful came into being... " ;-) ) and needed a very sad face for one of the pics.
THOUGHT I had seen wet eyes recently - but that was tricky lighting and/or photoshop in your "Empty chairs at empty tables" series, Caelrya.
THOUGHT I had seen some tears in "that other face" series by Kayol - but those were probably just my own ;-)
so yeah - no idea. Actually a few ideas.
Complexion.
A special "tear" jewelry/piercing that can be attached to the eye
A warpaint (nah, probably to flat)
Postediting in Photoshop - lots of "wet eye" and "tears" tutorials out there - but I hate postediting.
Best of course would be a "real" water source in the eye, physically correct rolling of tears, leaving wet stripes on the face. Add reflection/refractiong/glittering, everything fine 
Wet & Cold and some of the shower mods have a little bit of that - for the body.
Maybe some stealable ideas from there?
will have a look around if something like this exists in other games - it is actually the first time that I develop an interest in the topic.
Oh, and LOL Kayol, yes: the flow of information in the unseen is a funny thing. But don't worry, I do not know what Saga story is coming up next ;-)
Update: quick search only revealed a couple of crying mods for The Sims
- they look horribly manga, but show the general approach (overflowing overlay in lower eye, tears and wet strips on face.)
Examples: here and here (slightly better)
Update2: getting closer, found a mod (or rather modder's ressource) for tears in Oblivion - here. Maybe some of the cracks here could improve that and port it to Skyrim... from description: "this is a hackjob. It's a decal that is placed in front of the face, so it will mostly work well on characters with normal head size that are facing towards you."
Update3: ...and someone already had a go at the Tears WarPaint approach, woohoo: thread here , download is a bit down the page - will give that a shot later, may that is already all I need for now 