[1]Recite Sayyid al-Istighfar (the master du'a for forgiveness) once daily with yaqeen. (Bukhari 6306)
[1]Know that whoever makes istighfar, Allah provides from where they do not expect. (Qur'an 71:10-12)
[2]Seek forgiveness in the last third of the night — Allah descends and asks who is seeking forgiveness. (Bukhari 1145)
[1]Combine istighfar with good deeds — good deeds erase bad.