Aye, there's also the material aspect of cloud-making. Look for VanLippe's cloud materials online, they are the best in the Bryce industry, and will teach you volumes (hah!) about the DTE and volumetric materials in Bryce. These can be applied to spheres, which is how I made the dark foreground in my latest scene, or applied to Volume Slabs and put high in the sky for very realistic cloudscapes, all Brycean...