one answer simlilar general than your question would be: dedicate time to study graphic design with an emphasis on image processing, rendering and composition.
If you interested in how this particular image was created/composed/rendered I suggest searching one of the advertisment graphic design portals to see wether there is detailed information available. 🙂
This came up in web search results:
It seems like Ricardo Barcellos and others like Evandro Malgueiro did that at Zombie Studio for a former agency called Young & Rubicam (Y&R) in São Paulo with tools like Pixologic Zbrush, Autodesk Maya or 3ds Max. Y&R meanwhile united to an agency called VMLY&R, that is part of WPP, one of the world's largest advertising companies. The client was Grupo Petrópolis.
Maybe ask the artists themselves at Behance, the 3D-Studio or the agency to get further details about the project or search the web with that info to find out more.
It’s a combination of old-fashion set photography and digital-imaging post-production. Lots of PS layers to enhance the clarity and saturation of every component of the image.