Another buy from AliExpress, some metallic gold and silver self adhesive nail stickers.
My daughter tried these out, I have to say without success. Mind you she was in a great hurry as she she was going away on her hols to Greece the same evening. I think she somewhat rushed and they came out crinkled and creased. She was not happy and they came right off. But I think with a little bit more time and effort these would go on smoothly and look fab.