What is easier to work with when designing abstract surfaces, making 3d curves out of existing curves and then creating surface from those 3d curves - this is from one of car modeling techniques that I've done. Or are there other ways?

If I was to make something simple like car hood, which would have 4 curves, 2 of wich would be rail curves and the other 2 would be start to end curves.

By abstract I was thinking something along of adding more rail curves and have the surface follow that, creating sort of bump in the middle with these extra rail curves.

I wanted to know if there is some material on the internet, even if it's simple non complex example it would help. Or if someone has experience with this kind of design.

Thanks