1). Confession is all about receiving the forgiveness we have all already been given. We cannot earn forgiveness by works, attitude, or even confession itself; if we could, it would be a wage not a grace (i.e. a gift).
2). Penance is not a punishment for sin. Completing the penance you've been given is a sign that you have received God's forgiveness and resolved not to sin again. This is why I always assign sin-appropriate psalms as penance.
3). Priests rarely remember the sins of individual penitents. Some believe that this is a grace from God given so that the confessor is spared the difficulty of carrying around the memories of sin. Sounds good to me. Frankly, I think the explanation is more mundane: priests have heard it all and sin is boring.
4). Explaining your sins in the confessional is unnecessary and time-consuming. Just say what you did and leave it at that. If more info is needed, your confessor will ask. Explanations generally come across as attempts to excuse the sin.
5). Ask for counsel if you need it. Most experienced confessors will know when counsel is needed, but it never hurts to ask. Just keep in mind that there are others waiting to confess!
