Good question. Except the different color bands from the regular and premium lines as you already mention, it is difficult. Of course, color, size, shape and taste is a definite indicator. Once you smoke them, it's not possible to distinguish between the bands, e.g. which black band belonged to which.
I do keep my Don Carlos's cigars(my peronal favorites), in their own box(partially opened,of course) in my Humidor.
Ed