It seems like it would be a lot of work, but it might be fun to astetically change visuals of skills to match it’s level.
An example would be Pavise looking like a piece-o-junk wooden board from levels 1-5, then being a regular shield levels 6-14, and finally a shield with spikes sticking out at 15. Or the fire from fire attacks being much more intense. Maybe more glowing symbols in every cure square?
Wouldn’t it make you feel that the skills have much more of an ‘umph’ when you put all of your points into it? It could also be a visual indicator for PvP.

and I even think actual skills would benefit from having a slightly more powerful looking effect at a higher circle.