Since all these cards are now published, I think I'll give you a little more insight into the method by which the cards are created. Contrary to what many people think, the artists who work on Magic do not sit in a basement doing multiple paintings, hoping that Wizards of the Coast chooses one or two to publish. That would be a terrible business model for both artist and publisher.
I get a very specific description of the assignment, and I try to work that concept into a visual composition. I send out sketches to the art director, and either he likes one of my ideas or we go through a series of revisions until it is right. Here are some sketches from the most recent cards. Same concept, different compositions.