For the stockings on Collete Du Bois and Cassandra, I decided that harlequin diamonds would be pretty appropriate. When I went to shade this freehand, I treated them similar to the way I would treat jewel effects (ie, highlighting up towards the bottom).
Another point of interest is that I actually lined the lips. I do not always do this because I often want makeup to fade into the face, but I found that in this instance it allowed me some added expression on the faces (lining the lips allows you to alter the line of the mouth to extend it in a number of ways that create an expression). That is something I'll definitely be doing more of.