Cool! I think the dragon piece has a good use of color. Your vanishing point(s) is(are) kind of close to the image itself, which is causing the foreground block to distort a bit. You can create a big document, place your VPs, and then focus in on the area you want to have your finished image in. Creating an overlaying mask will help you to remember where you’re composing the image, too, if that makes sense. Make a layer, fill it with black, drop the opacity so you can see the VPs, and cut out about where you want the image to be. Also, keep in mind that the castle will have some wear and tear, so perfectly straight lines are strange to see.
For the “Forest Sage,” maybe there could be some more contrast in the background trees not in the light. Everything feels like it’s in a narrow range. so maybe adding a little more contrast around the edges of the piece will help make the lighter, less contrasted area in the middle pop more, kind of like a subtle vignette.
You might want to venture into some material studies. The dragon’s wings are a great opportunity to study subsurface scattering. The Buddha statue would be another one, too, for metallic surfaces. The castle would have some deposits from rain water as well as things growing on it with a rocky surface underneath. Pretty neat doodle ideas, though!
