Of course...

We all slip up. If you do something terrible (like insult somebody unintentionally) or anything, it's a whole lot easier to apologize and fix the whole mess before it gets blown out of proportion. Try to avoid doing it in texts, emails (read: Facebook), or over the phone- you lose a large, large portion of the nonverbal communication you get when talking face to face. Honestly, if you mean it, just say you're sorry. It's definitely easier and nicer to ruffled feathers if you immediately say 'Man, sorry- I didn't mean that, really.' or 'Oh, I'm so sorry!' right after you blurt something mean. Even if you say something really bad by accident, just show that you're sincere about it. I myself have said really mean things, but in about one-point-three seconds I think to myself -damn, that sounded pretty bitchy- and I turn (and wince) and say sorry. Eye contact is again important. Ah- another important tip. DON'T BE LATE FOR SCHOOL!