Here's my method:
undercoat with grey car primer (for
uk users - from Halford's)
base coat of rotting flesh
dipped in quick drying wood stain - light oak - from wilkinsons
coat of thraka grenn ink
coat of develan mud ink
brazen brass washed with a mix of the old green & brown inks. this was left to dry then a wash of vile green and finally a dry brush of brass to blend down the vile green.
bleached bone washed with a mix of the old brown & yellow inks
rusty metal (not finished on the marines) - dark flesh base coat, then vermin fur & blazing orange then a dry brush of bolt gun metal then flecks of bolt gun metal painted on.
the models then had areas stained with baal red and the old red ink.
& an example: