Dua - When leaving the house

Prophet (SAW)'s Prayers
When leaving the house
Recite:
بِسْمِ اللَّهِ تَوَكَّلْتُ عَلَى اللَّهِ وَلَا حَوْلَ وَلَا قُوَّةَ
إِلَّا بِاللَّهِ
"I depart with Allah's name, relying on Him. It is Allah who saves us
from sins with His guidance (the ability to do so)." (Tirmidhi)
It is stated in the hadith that if a person recites the above dua and
departs then there is an (unseen) procalamation that his need will be
fullfilled and that he will be protected from any harm or injury. On
hearing this dua, the Satan goes away from the place and refrains from
troubling the reciting person.
(Tirmidhi)
Also look towards the skyand recite:
اللَّهُمَّ إِنِّي أَعُوذُ بِكَ أَنْ أَضِلَّأَوْ أُضَّلَّ أَوْ أَظْلِمَ
أَوْ أُظْلَمَ أَوْ أَجْهَلَ أَوْ يُجْهَلَ عَلَىَّ
"O Allah, I seek refuge in You from misleading or being misled or
oppressing or being oppressed or from being ignorant or bearing the
result of ignorance".
(Mishkat)