It's not so much the Marks that I'm impressed with, but the card backgrounds. How do you decide on what you want to design for those?
i just try to see which features the elements have in common, or how they could be "updated" by an other element. Is not easy for all elements combination, so i'm starting with the ones i'm more sure about. As for the Marks, they are merely a different configuration of the pieces of the old ones, i don't wanna create a new one for them, so it's easy not to be impressed by them.