Oldschool things that made FF great back in the day is the right way to go. Like Del said, things like this do factor into the interest of the game. I didn't want to be a Conjurer, i wanted to be a White Mage with Cure Level 1... Its more iconic.
I also hope they would have talent trees too to differentiate your character. Or just something along those lines. The Gem Slot passives in FFIX was good, or a form of the Sphere Grid might be good too. You can even have a square board that you unlock through levels/items, and insert bonus items in varying shapes to fit the board strategically(maybe craftable) to help make your character more you. Even Tabards from WoW that do nothing but have visual appeal is good. Moar customization!