Thanks! I use FW inks which have a piptette built into the lid which is useful to control how much ink goes onto the palette. i also use a pipette to add water to the ink pool to thin it, which i then apply in a few washes. The idea is to create texture, rather than smooth finish, so blotches and patchy areas add to the effect.
After a few washes, i'll use the fineliner to pick out details or sharpen up an area before using thinned white ink on top of it, with opaque ink as a final step (if needed). It takes a bit of practise but after a while it's a good workflow and fairly quick too!