Apologizing and Saying Sorry

In order for an apology to be truly effective you need to consider not only what needs to be included in the apology itself, but also how to extend it.

Give a detailed account of the offense. You and the hurt party need to be clear on what it is you are apologizing about.
Take responsibility and recognize your role in the situation. Make no excuses and don't lay the blame on anyone or anything else.
Acknowledge the hurt or damage your actions caused.
Express your regret clearly and concisely. Don't talk about larger issues just the incident itself.
Promise that it won't happen again and if possible show the injured party what steps you have taken to help ensure that it doesn't.
Ask to be forgiven. Clearly request that you be forgiven and wait for an answer. This gives the injured party the well deserved 'power' in determining the outcome of the situation.
Time your apology well. The sooner you apologize for your mistake, the more likely it will be viewed as an error in judgment and not a character flaw.
Determine how to deliver the apology. Apologies extended in person or over the phone require that you be prepared for the conversation that will follow. While written apologies will give the recipient the time to think about the situation before responding.