Ok so first we have our tracks painted Leadbelcher or Tamiya Gun metal.
We then use a selection of various weathering powders in various earth shades. These are spotted haphazardly onto the tracks.
Here it is when dry after 4 coatings of White Spirit. I have gone for a slightly clumpier look for my tracks as Death Guard get everywhere. I will seal the tracks with purity seal and then possibly attempt the graphite finger tip technique.