The bit you need to learn is better definition - sharper, finer details, making the figures less "doughy". Those come down to skill with the material, which is mostly a mechanical thing you can learn, as well as a bit of patience for fiddly stuff. Now, a sense of size, proportion, motion, weight... that's more of an artistic thing, something requiring a good eye. They can still be learned, but have a much bigger natural talent component. So while I agree there's plenty for you to learn, I think you have the hardest part down already.