Kroot Hound:

 The following images show my initial work-in-progress coloring following a coat of Games Workshop White Spray Primer, a wash of several colors, and an initial mixture of paint. The spines were washed in Games Workshop Chaos Black, but I decided against a darker color for them and lightened 'em up in the finished version:

 These pictures show a semi-final version, with the initial greenish color lightened and highlighted a notch or two, the spines in a nice, pasty-looking bone color, and the tongue a happy shade of dark bluish-green:

 Here is the final final version, with the base done and a few last touch-ups here and there. (For example, the bone and metal trinkets on his spines have been tidied up...) I like the way the ground cover turned out, likewise in using colored background paper for this last set of pictures it brought out the true coloration a bit more:

•  I'm not sure how they match up with anything in Games Workshop's current paint line, but I'm using very old paints for the most part. From what I understand they're a little different than the new formula by their current (different) paint manufacturer, and some of the similarly-named colors have changed, I believe. (The old GW/Citadel Colour formula is now made by Coat D'Arms Paints, however.) For example, I'm using GW Striking Scorpion Green which was part of the Ork and Eldar Paint Set - it's similar in color to the current incarnation GW "Scorpion Green," but it's got a bit more of a yellowish tint to it.
•  I'm spraying everything with GW White Primer - I personally like the brighter colors that a white primer base provides and I've found it's much easier to "paint down" to areas I want dark than to "paint up" to areas I want light from a darker basecoat.
•  I also use a mixture of clear acrylic floor wax, dry time extender, and water to thin my paints. I've got the stuff in a pre-mixed bottle, and I just use small syringes to mix stuff a drop at a time as needed. For simplicity's sake, I'll just call it "Mix."
•  I use a small 6 well artist's watercolor palette for mixing colors. The colors I use aren't always necessarily exact, since I add paint by the drop and throw in a few more drops of white or grey or what have you, depending on how I think it looks. This is a general summary of the color-mixing scheme, though, and I think it's pretty much on the mark.

The Hound Skin:

 I started by putting a wash of 1:10 GW Codex Grey/Mix over the whole miniature, especially the skin areas. I received feedback when this was a work in progress from folks saying they liked the look of the "saddle bags" in the initial pictures - I had to chuckle since they were simply white primer with a wash over the top.

 The first layer of paint was a dark shade, and as it turns out I more or less completely covered all the flesh so I'm thinking I can skip the wash in future. I used 1:1 Codex Grey/Striking Scorpion Green thinned a bit with Mix. I highlighted all the skin with 1:1:1: Codex Grey/Striking Scorpion Green/Skull White and roughly 4 parts of Mix so as to thin it out so the paint was translucent. I went over all the areas of the body except for the darkest crevices and the stuff underneath limbs. I did, however, put a few thin touches on some of the highest areas of "dark" parts, like the knuckles and smooth areas of the legs.

 This is about where the 1st pics were taken. Nothing painted but skin, although I did put a wash of Black over the spines since I was thinking they'd look good dark - I reconsidered after the fact.

 I went back over most of the areas once with a 2:1:1 blend of Skull White/Codex Grey/Striking Scorpion Green again, thinned a bit (1:4 paint/Mix concentration or thereabouts.) I went over the extreme highlights a few more times with the same blend - since my paint is translucent it lays down more when I go over it repeatedly. I also control how much paint I deposit on the mini by how long I leave the brush in the paint puddle on the palette - a quick dip and it's a very thin shade, a longer soak and it's more of the true color.

The Spines and Underbelly:

 I had to backtrack to lighten the spines again, but if I repeating from white primer these would be the steps:

•  A wash of 1:10 GW Brown Ink/Mix over the spines and underbelly for shadowing.
•  I layered 1:1:1 GW Brown Ink/Bubonic Brown/Bleached Bone at roughly 1:4 paint/Mix over most of the raised areas, only leaving straight Brown Ink in the deepest recesses. For the spines, this was just a layer. For the underbelly, I think this ended up being more or less the final base color.
•  For highlights, I used a 1:4 Bleached Bone/Mix and applied this very selectively to the mid-range raised areas. (For example, on the underbelly I only touched up the areas closest to the sides and left what was under the Hound unhighlighted.)
•  For final highlights on the spines and blending the color of the spines out towards the tips, I added a drop of Skull White to the Bleached Bone. I might have touched up a few places with pure Skull White, but for the most part all the spines were a 1:1 mix of Bleached Bone/Skull White thinned out.

The Leather Stuff:

 I lined-in with 1:1 Brown Ink/Mix along all the areas where the skin met with leather/metal, touching up a few areas around the spines as well where I felt the dividing line needed to be darker. I also lined in some of the detail, putting a wash/glaze of sorts over the depressions in the leather and the stiching on the "water jug" and pouch.

 I layered thinned 1:1 GW Brown Ink/Bestial Brown over all raised areas of the leather, aside from the deepest depressions that were already as dark a brown as they could possibly get. This essentially brings me to the 2nd set of pictures (although the tongue was painted at this point.)

 I added a drop of Bleached Bone to the thinned Brown Ink/Bestial Brown mixture and went over the highest edges of the leather and a few extreme highlights on smooth raised areas like the folds of the pouch and sharp edges on the water jug.

The Tongue and Mouth:

 To start with, I painted the entire mouth and tongue area in several coats of thinned GW Chaos Black.

 Aiming at the time for a bluish color to the tongue and mouth, I then layered a 2:1 mix of Black and what I can only assume is GW Electric Blue (since it's an old paint and doesn't appear to match up to any current colors.)

 I didn't think the bluish color looked so hot, so I put a thin glaze (1:12 paint/Mix) of GW Snot Green over the tongue and mouth. In hindsight, I guess it would work out to be a 2:1:1 blend of Chaos Black/"Electric Blue"/Snot Green, but I did add a little something to lighten the mixture for the facing-outward sides of the tongue and the raised "tendons" at the base of the tongue.

The Metal

 This was the easiest and least involved area of color, by far. I painted 1:1 Brown Ink and a "gold" paint over all the metal areas. I've no clue what color the gold paint is exactly, but it's not GW Shining Gold and it's got more of a brown/green tint than GW Burnished Gold. I think Burnished Gold would be the closest color, though.

 The highlights for the metal were 2:1 Gold/Brown Ink. I essentially added another drop of gold to my palette and painted it over the top along the highest edges of the metal bits.

 This brings me to the 3rd set of pictures, although like I said the metal items and mouth were painted in the 2nd set. I tweaked a few things, added some highlighting to the trinkets on the spines, and painted the base. Hrm, I forgot to mention the eyes. The eyes are essentially bascoated Skull White, lined-in with thinned Brown Ink and given a thin glaze of GW Yellow Ink so they turn out to be a very, very bright almost-glowing yellow.

 All this may or may not sound really involved (hell if I know, but looking back over things here it looks like an essay!) I usually start with certain colors, add in drops of other colors, and, because I have a healthy dose of dry-time extender in with my Mix, almost everything I do ends up being wet-blended to a certain extent. I also intentionally "cut" my paint a little thinner than most folks seem to, so I can paint it on translucently and get gradual layering of colors, depending on how much paint I load on my brush. I'm a big fan of controlled washes, and I usually use these for shadowing effects, usually highlighting back up to and beyond the original color depending on the color effect I'm aiming for.

 The base is decorated with fresh non-clumping kitty litter and cornmeal. I tried out a new color/method for painting stone (for me) and it's got a yellowy-white tint to it that goes well with the miniature as a whole, I think. That's maybe for a different tutorial, though...