While the Sacrament of Penance should be received regularly throughout the year it is particularly important during Lent, as we meditate on both on the sins that permeate our lives and the forgiveness Christ pours out on us from His Cross. And of course all this is at the heart of the Sacrament of Penance (or “Confession”, or “Reconciliation”).

But how do we make a “good confession”? We begin by prayerfully examining our lives to recognize the sins we’ve committed since our last confession, i.e., “making an          examination of conscience.” This requires both honesty and humility—we must not kid,     deceive or excuse ourselves about anything we’ve done.
In particular we need to look for mortal sins, i.e., a sin that involves 1) grave matter, 2) full knowledgeof the sinful character of the act, and 3) complete consent. 

“Grave matter” means the act involves some very serious moral evil. While grave matter can sometimes be difficult to identify (some acts are gravely evil only in certain circumstances), but sometimes it is not. Clear examples of grave sin include (but are not limited to): violence (in word or deed) against parents, willful neglect of elderly parents, murder, abortion, drunkenness, abandoning a spouse or children, remarriage after a divorce (without annulment), sexual activity before or outside of marriage, viewing pornography, masturbation, contraception, theft of valuable items, lying about important matters, missing Sunday or Holy Day Mass,  receiving Holy Communion unworthily,  perjury, cursing someone using God’s name, dabbling in occult practices or witchcraft.

Also, in confession you must distinguish the “kind” of mortal sin committed, i.e., you must be as clear as possible about what the sin was, although you should refrain from being graphic or giving long explanations. So it is not enough to say “I had bad thoughts,” rather one should say “I had vengeful thoughts,” or “I had lustful thoughts,” etc..
Also, you must give the number of times you committed particular mortal sins. Sometimes this can be problematic, especially when one has been away from the sacrament for a while. In that case, give the priest some clear idea of the frequency or number; for example, “at least once a month for several years,” etc.

Finally, we should also consider venial sins, especially any vices (sinful habits) we have formed, as well as any venial sins that are particularly problematic—perhaps they might lead us to mortal sins, or cause others unnecessary pain, etc.

Some folks ask if they can take an actual written list of sinsinto confession. If that’s what it takes you to make a good confession, by all means do so.
Next comes going to confession. Many Catholics hesitate to go to confession simply  because they’ve forgotten or never learned exactly how it’s done. So perhaps a review of    details of how to go to confession might be helpful/