i usually start off with a scorched brown or a bestial brown,no shadeing .as i think those are dark enough then dry brush with a thinned down to the point of being milk vomit brown, after that and a lil bleached bone to the mix followed by bleached bone on its own. or try bronzed flesh, shaded with scorched brown ,or brown ink, drybrush again with bronzed flesh, mix in bleached bone and ficish off with blached bone on its own. another thing it to use grey for something similar to rotten wood or petrified wood
matt