If you are not sure how to think through what to confess, consider setting aside some time beforehand to make an examination of conscience.
What is it?
An examination of conscience helps you determine what to confess. It is an act you do before confession, where you take a little time to reflect upon your sins since your last confession. Many people use a sheet based on the 10 Commandments or the Beatitudes in Matthew, chapter 5, usually structured as a list of questions for to you consider and help you remember your life and relationships before God.
Ideally, you should take time before going to confession to pray to the Holy Spirit for light, thoughtfully work through one of the lists, and perhaps take notes to bring with you. Be sure to take note of your most serious sins, and prepare to name them in confession. Close with a simple prayer to the Lord for the courage to make an honest confession.
There are many examinations available online, and likely outside of the confessional. We are including three in languages spoken by Catholics in our diocese: English, Spanish, and Vietnamese.
A simple examination of conscience for adults, based on the 10 Commandments. (PDF)
A thorough examination of conscience for adults, based on the 10 Commandments and Precepts of the Church. (website)
Examination of conscience for married people. (website)
Examination of conscience for teens. (website)
Examination of conscience for children. (website)
If you like the idea of using an app, there is a very thorough examination of conscience on the Apple app “IConfess. (and others available for android and PCs).