Here is how I painted the big daddy Genestealer for my Broodcoven. This is the traditional Genestealer scheme and could easily be used on the standard Tyranids, Genestealer Cults or Acolyte models.

Genestealer Shell

1. Basecoat with 1:1 Kantor Blue and Abaddon Black .
2. In the very deepest recesses, shade with some thinned Abaddon Black .
3. Glaze the majority of the shell with Kantor Blue , pulling your brush towards where highlights should be.
4. Add edge highlights to everything with Sotek Green . In tight areas, keep them pretty fine, but make them nice and chunky around corners, curved edges and placed that would catch more light.
5. Edge highlight all of the areas that got chunky highlights with fine edge highlight using Temple Guard Blue .
6. Selectively highlight corners, curves and points with 1:1 Temple Guard Blue and Screaming Skull .
7. Finish with very small specular highlights of Screaming Skull , where you want the shell to glint.

Genestealer Skin

1. Basecoat with 3:1 Warpfiend Grey and Genestealer Purple .
2. Shade recesses using Druchii Violet . Rather than doing an all over wash, use a thin brush and run it into recesses, or shade via glazing.
3. Apply general highlights with Warpfiend Grey . This is very similar to the basecoat, so be quite generous.
4. Apply fine highlights with Slaanesh Grey .
5. Mix your Slaanesh Grey 1:1 with White . use this mix to selectively highlight corners and curves.
6. Finish with specular White highlights, where appropriate.

Where the neck meet the shell on the chest, I glazed it down by adding some Xereus Purple , then more selectively with pure Xereus Purple . I did this before the wash stage to keep everything unified.

Heat Vents

I followed the same method for the 'Genestealer Skin' on this element, with one difference. When it came to the shading, I washed it with 2:1 Druchii Violet and Volupus Pink , then highlighted as normal.

Black Claws

1. Basecoat with Black .
2. Apply chunky highlights of Dark Reaper .
3. Add a little Ice Yellow (or Dorn Yellow ) to the Dark Reaper , and apply fine edge highlights.
4. Increase the amount of Ice Yellow in the mix and selectively highlight. You might need to do this in a couple of progressive stages, depending upon the size of the claw.
5. Finish with specular highlights on the tip. For this, mix some White into your previous mix, to get a nice off-white.

Patriarch Brain

1. Basecoat with Genestealer Purple
2. Glaze with Screamer Pink , pulling your brush away from the centre, always.
3. Overbrush with 1:1 Genestealer Purple and Ungor Flesh , picking out the raised details.
4. Add fine highlights to the raised details with Ushabti Bone , going a little heavier towards the centre.
5. Selectively highlight with Ice Yellow , making them more concentrated towards the centre.
6. Finish with a few specular highlights of White , I bet you can guess where you should do more.

Pink Tongue

1. Basecoat with Screamer Pink .
2. Shade with Druchii Violet .
3. Pick out the raised details with 1:1 Screamer Pink and Pink Horror .
4. Add chunky highlights with Pink Horror .
5. Do fine edge highlights with 1:1 Pink Horror and Kislev Flesh .
6. Selectively highlight with Kislev Flesh .
7. Add some Pallid Wych Flesh to your Kislev Flesh and add a couple of specular highlights.

Yellow Eyes

1. Pick out the eyes with Yriel Yellow .
2. Selectively highlight with Ice Yellow towards the middle.
3. Finish with a small highlight of White in the middle.

Teeth

1. Basecoat with XV-88 .
2. Highlight with Ushabti Bone .
3. Selectively highlight with Screaming Skull , towards the tip.
4. Finish with a dot of Screaming Skull , mixed with some White .

Worn Steel

1. Basecoat with Leadbelcher .
2. Wash with Basilicanum Grey . I'd advise using a damp brush, and pulling pigment towards shaded areas.
3. Repeat with Agrax Earthshade .
4. Drybrush with Leadbelcher .
5. Add general rust in recesses with thinned Skrag Brown .
6. Enhance the rust with a smaller amount of Balor Brown .
7. Highlight with Silver RLM01 Metallic .

Copper Detail

1. I base coated with a Bronze from Darkstar, but use whatever bronze you have to hand.
2. Now wash with Agrax Earthshade , with just a touch of Sotek Green in in it, roughly 1:6, if I had to give a ratio.
3. Re-estabblish the Bronze where necessary.
4. Add some oxidisation with some very thin Sotek Green . If you get it nice and watery, you can flood recesses and glaze areas easily.
5. Once dry, add a little White to your Sotek Green and cover a smaller area.
6. Finish with a very small amount of pure White where you want to really enchance the look.
7. Now add a little Silver RLM01 Metallic into your Bronze =, and add some chunky and edhe highlights.
8. Finish with a few selective Silver RLM01 Metallic highlights, where needed.

Cobwebs/Stringy Goo

1. Basecoat with The Fang .
2. Wash with Drakenhof Nightshade .
3. Now mix some White into your The Fang and pick out all of the edges you can.
4. Increase the amount of White in the mix and selectively highlight on very prominent ridges.
5. Increase the amount of white AGAIN, so you have a very pale off-white. Then add very small highlights. These last two stages are best done where the "strings" meet the rest of the model.