Yes, you have to think in terms of volumes, how they interrelate, what it communicates and what that means. Then there is the aspect of how it will look right in front of you in real life. This is a very important step and only advanced designers can make that translation well. For example the Renault ZOE Z.E. concept, the Smart roadster, the new Smart, Nissan Juke, Citroen Cactus, were much better as sketches.
Here is a good inspiration page: