I think it would be a good idea to point you to the Scourges and Reavers section of the Aphotic Gallery, in case you didn't know already.
I have to admit my entry's Scourges' bat-ish wings look rather crappy.
I made the "hand"-part the same colour as the hair and the membranes the same as the skin, which i later found out, via google picture search: Bats, is mostly incorrect, zoologically.
I think the correct answer would have been to make the whole wing in varying hues of the skin colour.
Tried to drybrush, which failed hard, because there is no structure on the membranes and i probably started off too bright already:
Shading is difficult too, at least the way i did it (shading last) ended up pretty blotchy:
Maybe also a result of the lack of structure, or i just messed up(shade not thinned correctly?), or both xD
Probably will have to repaint those wings, some day...
Especially this one:
What a terrible freehand, i tried to paint a Marker from Dead Space.
Didn't work out AT ALL.
Quite happy with everything else, and the feathered wings too, though:
Good for drybrushing and shading.