I finally finished my Forge World Blight Drone. This model was a lot of fun to paint. The amount of detail on the model is incredible. The combination of mechanical parts and flesh is a lot more grotesque than other Daemon Engines. Which is perfect for Nurgle. I'm planning to convert a Forge Fiend and a Helldrake in the same style as Forge World did this model. Still not sure how to achieve this, so if anyone has any tips or ideas that could be relevant, feel free to comment.
The models armour was done in the same way I do my World Eaters (check out the tutorial: http://wilhelminiatures.blogspot.no/2015/03/tutorial-heresy-era-world-eater.html) only glazed in GW's Sepia shade. I really like glazing white with sepia. It sometimes gives the model a greenish look, which is perfect for Nurgle Armour.
The skin was done with light human skin-tomes, shaded and glazed with purple to give it a more sickly feel, and to contrast the armour.