I considered a lot about more efficient process.
Thus, I made 3D model while looking rough key sketch and inspiration images,
and then finished the design by sketches and scribbles of necessary parts.
I set a dimension of the vehicle first, and then design Type-A,B,C in there. So, eventually, I developed this as the final design that I really like.
By this process, I could save the energy, and control in a proportion and position without exaggeration.