As I have a few decorated nails to show you, too.
The polish I used for a base here is from Catrice - Miss Piggy Reloaded, applied in two coats.
Then I applied on part of the index and thumb nails silver glitter and when it was dry I just outlined the petals of the flowers using black and white acrylic paints.
And then the other elements and swirls.
Finished with a coat of Seche Vite top coat.