How should Catholics prepare for Mass?

Catholics prepare for Mass by examining their conscience, ensuring they are in a state of grace (going to Confession if necessary), observing the Eucharistic fast, arriving early for quiet prayer, and approaching with faith and reverence, disposing both body and soul to receive Christ worthily.

Examination of Conscience and the State of Grace

Even for those free from mortal sin, an act of contrition and humble acknowledgment of venial sins helps purify the soul and heighten the disposition of heart needed to meet the Lord worthily.