Most fantasy skins are made with stock photo's and such, so they lose that more painterly quality Maxis match skins have. For a start, have you seen
Berrynooboo's skins? In their
Resources page they also link to skins and make-up they use. (The make-up link is a bit hard to see, here:
http://berrynooboos.tumblr.com/post...our-sims-makeup)
Of course, Berrynooboo makes make-up themselves that add a fantastic flair:
http://berrynooboos.tumblr.com/tagged/CC:Makeup
In other words, the easiest thing would be if you combine colourful skins with some fantasy-CC make-up. There are some Maxis-Match fantastic skins out there, but there are much more coloured 'plain' skins.