I do reference *very* closely - it gets boring, and I don't do many like this, but I'm not good enough to just abandon the reference and fly yet (sadly >.<) but it's not a paintover.
The face was from
[link]and the hair colour
[link] and
[link] (I should link, but the photos are all over the internet so I'm a bt uncertain where to link to. A google on 'Amber Benson" brings them up quite quickly)