Here are some guidelines for confessing an offense from Ken Sande's book The Peacemaker. 

1 - Address everyone involved. If you’ve done something that’s affected more than one person, then everyone who’s been affected needs to hear your confession. That means if your sin is habitual gossip, you probably need to apologize before the whole church. Or whatever the sin is, a good rule of thumb is that the circle of confession needs to be as wide as the circle of offense. In a church I used to attend, there was this one guy who apparently had a bit of a temper, and after the church service one day, I’m not sure exactly what happened, but he just blew up on another guy in the church, and a lot of people saw it. So the next Sunday, he apologized before the whole church, and I thought that was very appropriate. So number one, address everyone involved.

2 - Avoid “if,” “but,” and “maybe.” These are the words you absolutely do not want to use in an apology. I’ve only been married for a little over five years, but even I know that if I use those words in my apology, it’s probably not going to go very well for me. “Honey, I’m sorry if I hurt your feelings, but you’re just so sensitive sometimes.” Not the best thing to say. So avoid those words “if,” “but,” and “maybe.”

3 –-Admit your wrongdoing specifically. It’s not enough to apologize for “everything I’ve done against you” or “all the bone-headed decisions I’ve made.” Show them that you understand exactly what those bone-headed decisions were and why you need to be sorry for them. They know what you did, but they need to know that you know what you did.

4 - Acknowledge the hurt. Put yourself in their shoes and think about how they must be feeling, and then say something that shows you understand. Show that you understand how your action harmed the person. Show some remorse for the pain and difficulty it caused.

5 - Accept the consequences. Accept that it may take some time for you to earn back that person’s full level of trust. Accept responsibility for any material damage you’ve done and try to make restitution for that. Actions have consequences, and if you’re really sorry, a good way to show your sincerity is by accepting those consequences.

6 - Alter your behavior. Have you ever had someone tell you they were sorry for doing something only to do it again soon after? And perhaps the second offense was followed by a second apology, but then, lo and behold, it happens again? I’m guessing that after two or three cycles of that, their apology probably wouldn’t mean very much to you. If you’re really sorry, you’ll change your behavior.

7 - Ask forgiveness and allow time. You need to directly and specifically ask their forgiveness for what you’ve done. Now, keep in mind that, depending on how serious the offense was, it may take some time for them to forgive you. So for a more significant offense, don’t expect them to be ready to fully forgive you and move on with life five seconds after you ask. But you do need to ask.