Make use of highlights
I create a new top layer and call it Highlights. It’s time to shift back to the lit areas. (I jump from shadow to light and back again to keep everything balanced.) I select the Color Picker, grab some direct light colour and brighten the colour up significantly. Then I paint areas that require a bright highlight. I also start adding rim lighting and some deeper shadows.
An autumnal background
Next, I create a layer underneath all layers and name it Background. Using a natural brush I very quickly start laying in some autumnal colours to complement the greens of the creature. I treat it loose and abstract, and use darker values to ensure that the creature pops from the background. I then click Filter>Blur> Gaussian Blur, and set the blur at 25 pixels.