as with all images, it depends on where you start.
I would begin with curves and a gradient map adjustment layer.

well all you need to do is analysis the highlights, midtones and shadows..

so from what i see the image is:
highlights - cyan
midtones - yellow
shadows - blue/purple

this combinations can be made many different ways on photoshop so just try a few out
but i would say that curves would be your best bet

Well vignette and some desaturation no really trick

This is really a simplistic attempt at dual toning. The background is shifted green, the model is shifted red.