honestly i just drew this to draw them in my style and put detail into their regalia
i feel like celestias regalia is made of gold (obvs) with amethyst gems and pearl lining, while lunas is made of black titanium or dark silver? (if thats even a thing lol) with a moonstone on her tiara and diamonds or quarts or something that form the crecent shape on her necklace, both of which are lined with black pearls, meanwhile her shoes are made of glass with moonstone as well
as for their wings i feel like celestia would have eagle wings (passive soaring wings) while luna would have dove wings (elliptical wings), it has less to do with their actual flying and more to do with their designs in the show lol, celestia has eagle wings because theyre the biggest wings and she has the same wings as gilda in the show, while luna (and cadence) have dove wings because theyre cute lol, i feel like most pegasi would have sea bird or sparrow wings but thats debatable