What to say when you fear you may afflict something with the evil eye

إِذَا رَأَى أَحَدُكُم مِن أَخِيهِ، أَو مِن نَفسِهِ، أَو مِن مَالِهِ مَا يُعجِبُهُ [فَليَدعُ لَهُ بِالبَرَكَةِ] فَإِنَّ العَينَ حَقٌّ

English meaning

If you see anything of your brother that pleases you, or of his person or of his property [then ask Allah to bless him in it] for the envious eye is real.