I began a 63 Corvette. I did not make any sketches before, just doing it as it came to my mind, at that very moment. Why the Corvette? It may be because the bulges on the mudguards looked like traces of fenders in the old timers. So the main starting point was to emphasize on the fenders. I had to make them stand out.
So now let's begin the construction story:
 

The front of the car was cut out as shown. The cutout line followed the bulge bottom contour till the end of the hood opening.
The rear was treated the same way.
Styrene sheets were cut and glued at the back side.
The front fenders were made from styrene sheet by following the curve of the bulges.
The fronts were cut and glued in place.
The hood  and the circumferential side panel were traced on styrene sheet. The hood was given a slanting down curve at the front end.
The hood was constructed and the touching line contour between the hood and fenders were cut by try-and-check method.
The rear was fiiled with putty and sanded to smooth contours.
The joint between the top and sides of the hood was filled with polyester at the inside, then sanded to rounded profiles. The first pencil tracings of the front grille is seen lightly in this picture.
The front grille was made from the steel wire of paper clips. After being bent to the front profile, they were flattened by hammering and surfaces smoothened with filing.	.
The grille wires were joined by soldering and filing again.
I opened the grille recess, but while sanding I accidentally broke the tiny lower band. So I bent a steel wire to fit the profile and applied polyester over it for firmness.	.
I then added the center trim strip over the hood and sanded the whole thing smooth. Control was made by applying the primer paint.