Ordinarily, ripping lengths of deadwood from along the grain of a coniferous tree would quickly and easily create a pleasing and natural appearance to a jin. However, given the size of this stub, and its relatively short length, this method would have produced something of a "Parrots Beak" (an unnaturally sharply-tapered jin).
So my approach on this occasion had to be different and I decided to create the impression of a big jin with largely intact walls and a rotted-out core.