Damn, these are looking really good!
I'm already storing them in the folder with all the portraits dumped.
How are you doing these btw? 
I try to find Kojima artwork that looks the most like the character.


I load it up in GIMP and I cut them up in sensible layers. Hair, head and body for example. I remove what shouldn't be there and then work on new elements in separate layers. I cut stuff from other Kojima drawings, I trace elements from the anime artwork and use textiles from Kojima's drawings to add texture, …
So for Loretta I elongated the hair and modified the clothes.
Then I traced the bonnet from the anime artwork, used the textile from the clothe to color it in and used one of the filters to generate a texture that I then modified into something lace-like. Finally I pasted buttons and a rose from other Kojima artwork.
For Stella, I used the general outline of the anime corset thing to sculpt her body. I traced the ruf and integrated it with the clothing around her shoulders, I recolored and darkened the hair and tried adding the harsher highlights to compensate for it, integrating a rough trace of the anime's buns in the hair.
It's a lot of fiddling and trial & error. :p
(That's also why Brauner is still so rough, I have no good base Kojima drawing to work from)