Step 1: Draw dynamic straight lines. That means, fill hundred of papers just doing straight lines by hand. The lines should be what we call 0-1-0, that means, they start with very very low pressure, then become darker and darker until the middle point of the line, which is the darkest part of it, and then fade again until it disappears.
Step 2: Draw hundred of papers with geometric forms in perspective, especially cubes, following the same 0-1-0 tecnique in all the lines you draw. Draw construcction lines soft and colour the three different faces of the cube using lines.
That was my begining in transportatio design
PD: Use a nice and sharpened pencil