Loving the bull! These look wonderful! Food for thought, perhaps think of shapes like kneaded erasers or a similar, pliable substance. Make em bouncy and then weld them together where they intersect! You can measure it all but thinking of it as "chewy" specifically helped me. If you play around on Blender (because free) you can throw primitive shapes together and see how they will overlap. That's the idea. Primitives are what you are building from, so on the one hand you can make everything extremely geometric but when it comes to shape language, I think the joy of simplification is in the "texture" of what you are welding. Of course the preliminary is not actually a substance but feeling it as such as you operate assists secondarily in transforming from realistic depiction to cartooning or a hybrid thereof in the mental imaging. If you have seen Hercules (Disney's animated feature) I am sort of referencing Zeus when he creates Pegasus from the clouds. Clouds are amorphous and while you should definitely practice your cubes and spheres specifically to be able to weld anything in a measured sense, sometimes going outside and drawing clouds as they move slowly into varying forms helps to get the "wisp" into the hands. Drawing softly lets you layer shapes upwardly. The more control you have, the lighter a mark you can make and just wistfully indicate without overtaking the drawing via mark density of stroke. I hope this helps!