Before celebrating the sacrament of penance, each individual should reflect on these questions in particular:
1. What is my attitude toward the sacrament of Penance? Do I sincerely want to be set free from sin, to turn again to God, to begin a new life, and to enter into a deeper relationship with God?
2. Did I forget to mention, or deliberately conceal, any grave sins in past confessions?
3. Did I perform the penance I was given? Did I make reparation for any injury to others? Have I tried to put into practice my resolution to lead a better life in keeping with the Gospel?
Then, each individual should examine their life in the light of God’s word, and Jesus’ example.
Source: http://forgiven.dor.org/about-this-site/examination-of-conscience
