To follow up my previous post (click here), I can now show you the finished illustration.
I ending up working with ultramarine watercolour as an under-painting which can work fantastically well when you glaze colours on top, especially if you want a cool 'night time' atmosphere. So lots of thin glazes later I was finally able to build up the darker colours in the tree and the grass. I've found by building up the same colour wet-in-wet in clumps I can give a convincing impression of grass tufts.
For the finishing touches I used gouache, particularly on the fur highlights and the odd blade of grass.