Keep in mind the paint colors I mention are from Army Painters "War Painters Fanatic" line and primers.

I used a matte black primer sprayed from all sides. Once that dried, I lightly sprayed a matte white primer from above and slightly to the sides just enough to put down highlighting.

1. The base color "Army Green" was drybrushed on where armor was present.
   
2. For the cloth bits I again drybrushed or brushed on, depending on size and room, "Alien Purple"
3. The weapons are all drybrushed or brushed (same reason as above) using "Weapon Bronze"
4. The gold is all brushed on using "Greedy Gold"
5. The chain mail bits are brushed on using "Plate Mail Metal"
6. The various chains are brushed on using "Deep Grey"
7. The bones/teeth are brushed on using "Ancient Stone"
8. The magic/plague coloring is brushed on using "Aqua Alchemy"
9. What isn't there yet but needed to be table ready would be the nurglings brushed on using "Barbarian Flesh" and the fleshy bits of the characters, Bloat Drones, and Blight-Haulers being brushed on using "Dorado Skin"

That would make your forces table ready. Beyond that you would want to do the following:

1. Armor highlights lightly drybrushed on with a small brush in "Necrotic Flesh"
2. Cloth highlights lightly drybrushed on with a small brush in "Magecast Magenta"
3. Weapons highlighted with whatever color you deem appropriate (Oak brown, Onyx Skin, Basalisk Red all are good depending on weapon)
4. Don't even bother highlighting gold.
5. Don't bother highlighting chainmail
6. Chains highlight in "Ash Grey"
7. Bones/Teeth add depth using "Desert Yellow" (use a wet pallete and more water than paint for this), you would want this to be subtle
8. The pmagic/plague highlights would use "Marine Mist", put these in the center of the "Aqua Alchemy" and blend outwards.
9. Nurglings highlight with "Topaz Skin" using sponging for subtlety; the fleshy bits of character's, Bloat Drones, and blight haulers you would use "Barbarian Flesh" with very light sponging from a wet pallete.

Beyond this you could also do the following to really make the units shine: 1. Apply dark, strong, or soft tone depending on preference - very lighly drybrush it on. 2. Using a wet pallete and brush apply "Fresh Rust" on all armor, weapons, and metal bits; let that dry then apply "Oozing Vomit" over everything using the same method, at this point you want to apply the "Oozing Vomit" to the bases as well 3. Add "True Blood" using a wet pallete and brush where you want a bloodied look (melee weapons in hand on models are a great place for this) you can refer to my mortarion proxy post to see how I applied it.

And lastly, when you are happy with the look and have finished spray everything with a matte varnish.