Part of preparation for confession is examining your conscience, calling to mind the sins you have committed since your last good confession.
Fr. William Saunders tells us:
“We need to hold up our life to the pattern of life God has revealed for us to live. For instance, we take time to reflect on the 10 Commandments, the Beatitudes, the precepts of the Church, the cardinal virtues (prudence, fortitude, temperance, and justice), and the seven capital sins (pride, anger, envy, gluttony, sloth, lust, and covetousness).
“The examination of conscience is like stepping back and looking at the picture of one’s life in comparison to the masterpiece of life revealed by God. Remember when we were children, we used to trace pictures. Tracing helped us learn to draw. We would take a piece of plain paper, hold it over the original picture and then put it up to the window. The light would enable us to trace the original picture onto our blank sheet of paper. Periodically, we had to stop and step back to see if our paper had slipped and was out of kilter with the original or if we had deviated from the lines.”
A number of “prepared” examinations of conscience exist online and in print. We offer you this one from the Handbook of Prayers.