After Fard prayer the following Du'aa should be recited:
"Allaa-humma Antas-Salaamu wa-Minkas-Salaamu wa Ilaieka Yarji'us-Salaam. Tabaarakta Rabbanaa wa Ta'aa-laieta Yaa Zal-Jalaale wal-Ikraam"
(O' Allah! You are the Giver of Peace and peace is from You and peace turns towards You. O' our Sovereign Lord! You are the Most Auspicious, and the Supreme – O the possessor of all Majesty and Honour!)