Buff them for a more polished look, lightly scrape the backsides when cleaning them for a whiter look.
Filing them and smoothing the edge will help keep them from cracking, as will some hardener.
I don't use anything on mine, they are generally the same length, except for my left hand.
The left hand is shorter because of the way I use that hand for guitar playing.
They look nice, just need a little filing to look more uniform.