A short prayer before confession by St. Symeon the New Theologian:

O God and Lord of all! Who hath the power over every breath and soul, the only one able to heal me, hearken unto the prayer of me, the wretched one, and having put him to death, destroy the serpent nestling within me by the descent of the All-Holy and life-creating Spirit. And vouchsafe me, poor and naked of all virtue, to fall with tears at the feet of my spiritual father, and call his holy soul to mercy, to have mercy on me. And grant, O Lord, unto my heart humility and good thoughts, becoming a sinner, who hath consented to repent unto Thee, and do not abandon unto the end the one soul, which hath united itself unto Thee and hath confessed Thee, and instead of all the world hath chosen Thee and hath preferred Thee. For Thou knowest, O Lord, that I want to save myself and that my evil habit is an obstacle. But all things are possible unto Thee, O Master, which are impossible for man. Amen.