The Messenger of Allah (ﷺ) used to make dua to Allah by saying this:

اَللَّهُمَّ إِنِّي أَعُوْذُ بِكَ مِنْ شَرِّ مَا عَمِلْتُ، وَمِنْ شَرِّ مَا لَمْ أَعْمَلْ

Allaahumma, inni A‛oodhu bika min sharri maa 'amiltu, wa min sharri maa lam a'mal

I seek refuge in Thee from the evil of what I did and from the evil of what I did not.

Reference: Muslim: 2716