As one of my favourite builds in late 2017 here are my wip pics of Mortarion,
Deamon-Primarch of the Deathguard...
I built the model without much conversion, simply left those flying Nurglings on chains, cause they would be a pain in the ass for transport. Left the wings unattached for better painting, and magnetised them later for transporting.
Added some textures with GWs Agrellan Earth and Vallejo Texture paint,..also cut small grooves into the cloth-parts to imitate a rather raw material...
Put him on some sweets-can for priming,..went brown from below, green from the sides and top and at last bone from the top, all rattlecan (mix of GW and Army Painter).
Next step as always with my miniatures was a drybrush with Ulthuan Grey....
Adding base-colours, used with a wet-pallette, more like a glaze and after that again a light drybrush.
Most of the details are done with glaze-like colours, washes and drybrushing in between.
Added rust-pigments to the base, mixed with Vallejo Rust-Wash and after that a mix of Agrax Earthshade and Army Painter Brown Ink.
Repeat until finished ;)