So as I promised earlier here's how I paint my Death Guard.
It's worth mentioning that I spray my Death Guard white and then black out anything that is going to be metal, dark green, gold, ETC
Do two thin coats of Screaming Skull. Pick out the recesses and around the bolts with Seraphim Sepia.
Once that's dry clean up again with Screaming Skull and then highlight with white. I tend not to highlight every edge just the main/predominate ones.
SHOULDER PAD GREEN
Two thin coats of Waaagh Flesh, shade the recesses with Agrax Earthshade. Same as before tidy up with Waaagh and then highlight with Warboss Green and then edge highlight Skarsnik Green.
Base coat with Retributor Armor the was with Agrax Earthshade, gold again and then highlight with Runefang Steel.
Vallejo Flat Flesh (No. 70.955). Wash with Reikland fleshshade. Go back over the raised areas leaving the wash showing in the recesses and then use Pallid Wych Flesh for the highlight.
Use the same technique as the flesh except the Pallid Wych Flesh should be(think white heads) and then paint Nurgles rot over the entire thing (disgusting!).
For the gold use Nihilakh Oxide, wash it into the recesses and around the bolts on the gold sections. You can use this on the black sections as well. I use it sparingly on mine.
For the rust use Typhus Corrosion follwoed by a dry brush of Ryza Rust on the metal areas. I'd plan out where you're going to use it. I tend to avoid any kind of moving parts as the rust wouldn't "take" there. You can spread the Ryza Rust drybrush beyond the "confines" of the Typhus Corrosion spots if you like, it makes it's feel a bit more "natural" to me. Oh and Nurgles rot applied to any kind of sore, boil or anything that could be considered "icky".
Warboss Green, wash with Agrax Earthshade, go back over with Warboss then highlight with Skarsnik Green. Pick out any boils with the same flesh method as the Death Guard.
So there we go!