I'm not really one for creating fan O.C.'s — heck, I don't even have a "ponysona." In my fanfics, I typically leave the extras unnamed and nondescript beyond one or two notable traits.
Chiffon Veil (technically/retroactively) first appeared as the unnamed belly dance instructor in my first Equestria Girls fanfic CheeringSection. I would eventually bring her back and flesh her out in my third fanfic PartingtheVeil as well as Beautiful.
I loosely based Chiffon Veil on Suhaila Salimpour. While I've decided that she has brown hair, I want to avoid making her look too much like Saffron Marsala. I also describe her as "being the same age as Principal Cinch, possibly older, but radiating a youthful aura." At the very least, this ought to give my readers a better idea of what she looks like.