My painting method was this:
The skin was painted with different colors per Nugling, including Camouflage Green, Dead Flesh, Beasty Brown, Skull White, Bronze Fleshtone, Dwarf Skin, and Elf Skintone. Then, the horns and teeth were picked out with Skull White. Finally, certain bits were hit with Scar Red, Gory Red, Sunblast Yellow, Electric Blue, and Hexed Lichen. Then they were dipped using Minwax Polyshades Antique Walnut Satin varnish. After drying overnight, they were hit with matte spray, and then the bases were painted with Charred Brown, dry brushed with Beasty Brown, and then the glue/slime areas were painted with Squid Pink and Scorpion Green (a Citadel Paint I have).
The slime areas were done with the glue method that is easy and effective. What you do is put down some plain old Elmer's white glue, and then put some Zap A Gap or other favorite super glue on top of it. I occasionally slightly touch it with a pin or other tool to mash it around a bit. After drying overnight, it turns into an awesome pox-ridden/scabby/slime looking effect. I learned this from dvdhwk over at the Adeptus Arizona forums.
Here are the finished results! You can click on the images to see a very high-res image. I would love some creative criticism.