As Skaven are a horde army I've gone for a faster range of techniques than I would for a smaller force, with the hope that I can turn around well painted models at a faster rate than I normally manage and get the army to the tabletop. Having just finished my first 35 strong unit (bar basing, and possibly tweaking the banner and adding shield designs) I think the technique has been tested enough to share.
There are corners that could be cut for faster results, or greater detail to be added, depending on your preference regarding painting speed vs quality.
Below I've set out my painting steps, hopefully as a sensible series of stages to follow. I've interjected with musings about why I'm painting Skaven like so, hopefully sheading some light on my colour scheme.
Step 0. Assembly.
My models were all glued to their base, and armed with weapon and shield (as these are from the island Of Blood set the shields are part of the main body of the model) before painting. Had I been painting a standard unit I would likely have attached the shields as they don't block access to anything much. I'll be using (or at least trying out) GW's textured paint on the models so I did nothing to the bases at this point.
Step 0.5 Mount.
All the models I painted for this unit were mounted on the top of old paint pots with blutac prior to me starting work on them. It's hard to overstate how much easier this makes the experience of painting them, having something more substantial to hold than a base. The only issue I have is that these models will be magnetised, and I've had to delay doing that until after painting as the magnetic sheet I use under the base interferes with mounting (having had a play around with the idea, it seems that trying to use magnets to hold the miniature while painting doesn't work). If you intend to spray the models, you'll want to come back to this afterwards.
I was painting 24 models at once, which was about the maximum I could fit on my paint station at any one time, and still have room to work. Your mileage may vary with this. If any of the detail laid out below seems needlessly fussy about keeping track of things that is why.
Step 1. Undercoat.
Undercoat the models with a dark brown (I've used GW's old Scorched Brown). A Spraygun would make this very easy, but isn't needed. I recommend using a painting stick if you are going to spray them, so you can get the best coverage over a lot of models. There are lots of fiddly bits to get into between arms and body mainly, so you'll want to check each model has been fully covered, and fill in with a brush as needed.
Using the dark brown undercoat gives a lot of the model its finished colour (weapon hafts, shields, and fur) without much effort. It also provides a good base for everything else.
Step 2. Fur Base Layer.
I've used a mix of colours for the furs, with black, four greys and three browns, including the undercoat. At this stage you want to cover all the fur on the Skaven, making sure to get any at the base of the tail. There is no need to paint the shield hand however, as we can get that later with another colour. Make sure to catch any of the smaller rats at this stage, using a different colour to the larger Skaven they accompany.
I worked with a post it note listing the colours I was using and made sure I'd got the models arranged so I knew which had been b ase coated with which colour to speed up the next stage which is...
Step 3. Fur Drybrush.
Using a lighter colour drybrush the fur to your preference. I made sure to do all the models of one colour as a batch rather than keep changing pots, and to keep the different greys separate. You could possibly cut out this step if yo were happy with the look the base coat gets from washing.
Stage 4. Silver.
I used Leadbelcher to paint straight over the dark brown to bring out armour plate, shield rims, and weapons in silver. This only needed one coat and did a good job.Watch out for foot and shin armour, any talismans and tail weapons.
Stage 5. Bronze
Any metal left got a coat of Tin Blitz, to represent battered and corroded metal.
Stage 6. Nose, Ears and Tail.
I used Tallarn Flesh to paint all the tails, ears and noses, making sure not to miss any of the small rats out.
Stage 7. Muzzle, Ears, Hands and Feet.
I am going to try and find a good base from the new GW range to do this as coverage wasn't quite as I hoped, but here's what has been done so far. Using Elf Flesh I picked out the hands, and feet, careful to feather the edges of the join between skin and fur. At this point make sure to paint the shield hand as well. The muzzle and ears got a very small dash of colour, just enough to highlight the ear tips and give the impression of worn fur on the snout.
Stage 7.1. Open Mouths
Any Clanrats with open mouths had the interiors painted with Dwarf Flesh, before getting a wash of Baal Red.
Stage 8. Eyes
I went through picking all the eyes out in black, although red could also be used.
Stage 9. Teeth and Bandages
All teeth and bone got a layer of Dheneb Stone as this point. Make sure to catch any bone spines as well. I've left the claws as they were made light enough by the Elf Flesh, and imagine them to be covered in grime anyway. If I was painting a "cleaner" force I'd come back to the teeth with bleached bone, and maybe white, but seeing as I doubt Skaven care for dental hygiene this is where I left things.
Any bandages or strapping that was to be off white (rather than left dark brown) also got painted at this point. Keep an eye out for foot bindings.
Stage 10. Clothing.
The most time consuming stage I broke out a huge variety of appropriate colours and worked through the unit again and again until all the models had a new colour on them. You could easily cut down time here by using a limited palette, but I just can't see Skaven being that uniform.
Stage 11. Black Wash.
Any grey fur, bandages, white clothing, wood, and silver gets a wash of black. There's no need to be too neat. You'll want to let this dry for a while.
Stage 12. Rust.
Add rust to whatever degree suits, with the method detailed here. Depending on how you want the Skaven to look you could skip this step. The above has gone a little over on the orange. You'll want to tidy up any where your rust has hit where it shouldn't ready for the...
Stage 14. Brown Wash.
Everything bar the rust/silver, white cloth, and grey fur gets a wash of brown, giving a dingier appearance, and shading the model.
Stage 15. Finishing Touches.
I added a bit of verdigris to any metal that needed it, and anything else I'd missed.
Stage 16. Happy?
At this point you could add a highlight to the clothing, or reinstate the dryvbrush on the fur, but that seems to be a lot of effort when you've doubtless many more Skaven to paint.
Stage 17. What Next?
Once I've tweaked the banner colours I got the bases to do, which will mean a coat of texture paint, with a drybrush as needed, the addition of any static grass or tufts, then adding magnetic sheet to the bottom of each base, followed by finishing the edging with brown (Graveyard Earth for preference, although I may change to a new base paint so I only need one pass). A coat of varnish (possibly) and they'll be ready to die horribly on the tabletop.