Step 1: Base Coat
Get your marine primed in either Chaos Black or Abaddon Black, my preference is to spray in chaos black due to the matt effect and to cover any missed spots in Abaddon Black.
Step 2: Armour base colour
Now that your mini is ready, use Corvus Black to paint all the armour leaving the shoulder trim and eyes.
Step 3: Pouches And Seals
Using a detail brush, give the pouches and holsters a coating of Dryad Bark.
Step 4: Shoulders, Eyes and Seal
Using Khorne Red, paint the shoulders, purity seal and eyes. I paint mine as 3rd company so change the shoulder depending on which company you are using. With the eyes, I use a Army Painter Fine Detail brush, starting from the front of the eye, I paint backwards leaving a small section of the back of the eye black for a highlight (I will go further into this later in the tutorial).
Step 5: Aquilla, Highlights and Belt.
Using a fine detail brush, pick out the edges of the armour like in the above image, paying most attention to sections of the armour that will be hit by light. My advise for this would be to hold the model in front of you top down so you can identify this.
With the belt, I like to keep the base coat on show, and highlight the top and bottom of the strap. Also, pick out the joints if the armour.
The aquilla can be tricky to do, I would recomend watering your paint down to 75% water 25% paint and using a super fine detail brush, starting with the tip of the brush towards the base of the feather and stroke outwards.
Step 6: Aquilla Second Coat and Extra Highlight
With the Celestra Grey, water this down to the same consistency as the previous step as the brighter the paint, the higher the likelyhood of it "Chalking". Using your Super Fine Detail Brush hightlight hte Aquilla and any higher points of the armour, this will give your mini more depth.
Step 7: Purity Seal
Getting a small ammount of Zandri Dust, paint the paper of the purity seal.