Commas are a bit trickier, or at least I think so. I remember getting an edit of a fic back just *covered* with red marks instructing me to remove comma here and add comma there. The next fic I had from that editor came back with a whole bunch of added commas only, because I had tried so hard not to screw it up that I screwed it up.

:)

Comma abuse is less invasive and in your face than apostrophe abuse.