I also display mine in geographic order, but each state has it's own shelf. There are the exceptions when I put 2 or 3 states together.
My Ca lights, & Hi lights are on a shelf together, but geographically, Ca is the closest state to Hi anyway.
I did see something awhile back in the forums about SHURING up shelves in a curio, but didn't see the original tips, if someone could help me, I would really appreciate it.