I've been meaning to upload some of this for a while, as i've spent a load of time on a triptych of images, i'll show how they progressed from a semi rough stage to a more rendered finished piece.
I didn't screencap anything inbetween, but at this stage all I done was scan in 3 traditionally drawn panels, blown up to 165% of their original size, and then proceeded to lay multiply layers over it, working solely in greyscale. Once happy, I saved that option and added very low value colours.
And these are the coloured versions, as you can see, not much has changed in terms of value, only some areas i've focussed on with passes of colour.
Parallel to the digital renderings, I also done a more refined piece with my mapping pens, using the qualities of the nibs to accentuate the folds and directional aspects of the tree in particular (below)...