A slightly darker, deeper red cloth than what I normally use for my Black Legion tabards.
Model is sprayed Abaddon Black and then I thick edge highlight with Khorne Red . Don't worry too much if the edges are a bit transparent, as it helps fade into the black. Make sure there are defined Khorne Red edges before moving on.
Mix Abaddon Black and Khorne Red 1:1 and glaze the previous layer in to the black of the recesses.
Use Mephiston Red now, within the previous layer. I begin to stipple, scratch as I go to add texture, but these are Chaos models, so you could skip this or be more uniform on other models.
Thin lines of Evil Sunz Scarlet next, repeating the previous process but focus on higher edges.
To even the whole finish, thin Flesh Tearers Red in 2 parts Contrast Medium and use a large brush to cover the whole area. This really ties the black to the red.
Reestablish the Mephiston Red and Evil Sunz Scarlet layers. Again, add scratches and stipples where necessary.
Final edge and dot highlights with an equal mix of Troll Slayer Orange and Evil Sunz Scarlet , though Wild Rider Red would possibly be just as effective. Again, stipple and scratch.
Go back to the deepest recesses with Nuln Oil or thinned Black Templar . I went around edges of belts etc as well.
Cover the whole area with just Contrast Medium if the finish is obviously a mix of matte and the satin finish of Contrast paint. You can add a tiny drop of Flesh Tearers Red if you want to build the red up more.