Clark Ashton Smith was a multi-talented individual. In addition to his verse and prose writing, he also drew, painted, and sculpted. A good selection of his artwork can be seen here. As an example, here's a little idol of the frog god Tsathoggua that CAS sculpted:
I know there are people out there who'll find this sculpture utterly unremarkable and argue that it's "childish" or "amateurish" or some other such term of derision. From my perspective, though, it has a powerfully primitive look to it that makes it appear as if it were the product of some prehistoric human culture that actually did worship Tsathoggua. A lot of Smith's art has a similar quality to it and I can't help but find that appealing.
Several years ago I had a dream of writing three related RPGs based on Hyperborea, Averoigne, and Zothique. Though I had permission from Smith's estate to do so, the thing became entangled in legal oddities, since Arkham House claimed -- dubiously, I might add -- to hold the copyright on Smith's texts and that I'd have to pay for the right to quote any of them at length, which I had hoped to do. Not knowing any better back then, I simply abandoned the whole project. I regret having done so for many reasons, but one of the big ones is that I had had a plan to commission artwork that drew on Smith's own as inspiration. That would have given the whole thing just the right "otherworldly" air to it and certainly set it apart from anything that'd ever been done before in the RPG field.