As a part of the materia system it would be neat if we could add crests to shields, shirts and breastplates. By crests I mean the city crests, or perhaps a guild emblem. I realize it would make additional work when creating item graphics, but it would add a way to make an item more unique than choosing between three or four colors when crafting, and it would really personalize an item for the player.
Sorry if this idea has already been posted before.
Edit: We should be able to add runic designs to sword blades as well. This could be open to all crafts with a goldsmith adding gold inlay to a blacksmiths work, or a culinarian adding the Gridania crest to a wedding cake.