When the Prophet ﷺ broke his fast he would say: “Dhahaba-ẓ-ẓamaʾu wa-btallati-l-ʿurūq wa thabata-l-ajru in shāʾ Allāh” — “The thirst is gone, the veins are moistened, and the reward is confirmed, if Allah wills.” (Abū Dāwūd — ḥasan).
العربية: عن ابن عمر رضي الله عنهما قال: كان رسول الله ﷺ إذا أفطر قال: «ذهب الظمأ وابتلّت العروق وثبت الأجر إن شاء الله». (أبو داود).
Memorize this short duʿā and say it after your first sip or bite at iftar.