I think the best thing is a lil'bit of 'How I did it...'. This is my dummy tut

Start PhotoShop or any retouching program. Load the V3 Face map of your character (or a seam file, but I prefer to work directly with the same face I want the effect). Create a transparent layer. Paint your tears there as you prefer. I recommend airbrush at 50-75%, try smooth edges, but the most detail you use, the most result (see Neftis' map). Create a new layer between the original map and the tears one. Fill it with pure black and save it as *jpg with a different name, for example 'displ.jpg'. Now you have your tears map without modify the original face map

Remember: it only works rendering with Firefly (P4 render NOT) and 'Use displacement maps' checked

CASETTE
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"Poser isn't a SOFTWARE... it's a RELIGION!"