I struggle a lot with this. I've just listened to Fr. Ripperger's talk on language, and it really brought home how awful this habit is, especially for a woman (which I am). Other than mentioning it in confession, how can I rid myself of this habit?
Talking obscenities is a terrible and vulgar thing and *at first* a terribly difficult habit to break. I say *at first* because after only a short time it becomes less and less difficult, but ya gotta start now, you need to start *continually* watching your mouth from this moment on. Do this, and you will find it's like anything else, you *will* break the evil habit.
If you use God's name in vain at all, it is most important for you to stop doing that immediately, never do that ever again no matter what because *that* is a mortal sin.
It's not a mortal sin to occasionally say the typical cuss words, but if (God forbid) you were to have a car accident, your last words should be "Blessed Mother" or "Holy God" or "My Jesus" or..... you get the idea, so you do not want your last words to be "oh f___" or anything like that - so get out of the habit starting right now.
Eph 5:3 But fornication, and all uncleanness, or covetousness, let it not so much as be named among you, as becometh saints: 4
Or obscenity, or foolish talking, or scurrility, which is to no purpose; but rather giving of thanks.