Having trouble creating realistic blood decals (caution: blood reference)

I’ve been unable to create convincing blood stains/puddles with a decal. I’d like it to darken the surface and maintain some of the underlying surface’s texture where its spread thin and also build up to be more opaque, reflective and smooth and retain it’s color where it is thicker. Can anyone direct me to a tutorial or a an example with a breakdown? All the tutorials I’ve found use the emissive setting to a small degree which creates real inconsistent outcomes under different lighting.

Sorry for the gory reference