I am sorry I often preface meaningless and insincere apologies with the words 'I'm sorry'.

Now supposing, for the sake of an argument, that you have had to stab a close personal friend in the leg with a pencil because you were bored. The best next step is to send along this wrongcard - or maybe one that seems more sincere. Whatever. The point is they'll appreciate the apology. And they really won't expect your next attack.