I was just wondering if anyone could provide any insight as to how this effect is achieved?
I'm aware that dodging and burning is used, I've tried that my self, but I can't quite match the effect seen in the picture above. My method is done by creating a 50% gray filled overlay layer and then painting white and black on that.
I'm missing something though, I can't achieve that surreal effect.
It's a heavy colour grading process, we did a lot of work like this at my last studio job. There's really no exact formula on how to do it, it's basically using a lot of curves and levels and other colour editing tools, combined with a lot of painting and hands-on tweaking. The head designer at my studio used to call it "digital make up", and that's fairly apt.
When you do it appply the colour editing tools as separate layers on top of the image (non-destructive editing), and then use brushes to paint over certain areas, using either colour or burn and dodge. High pass and inverted high pass will also give off a crispness, and you're going to want to use a lot of masks to edit select parts of the image. The blur tool will also be quite essential to give you that smoothness, just make sure you're not actually making things look blurry.
Jobs like these are almost about as much colour grading as they are illustration. And of course it helps if the photo comes from a good HDR camera. Most photography courses now teach you how to do post-editing in Photoshop, otherwise there's also loads of colour grading tutorials online (such as this one, this one and this one to name a few).