This last one is superb
Lasa.
As for my own efforts, I've given it some thought - I think part of my problem with the Selective Color & Hue & Saturation layers were that I still applied it to the whole skin area - I should actually apply the various layers to a smaller mask within the "skin" - this should've been obvious to even a beginner such as myself! This will allow greater skin colour variation (with plenty of control) which will add to the realism of the colouring.
I'll give it a try now and see how it goes.