Someone should put together a grammar of cursing. What is the "decorum" for using certain words? When are they socially required? You could do a study of David Mamet's use these words (or better yet Elmore Leonard) and compare them to a transcript of real speech. Cursing should be

1) Casual. You don't use the word in order to use it, but as a part of an idiomatic expression. It doesn't call too much attention to itself, although it definitely is a mark of register.

2) Idiomatic. It's got to be the right idiom, in the right tone of voice, at the right time.

3) Rhythmical. It has to recur at certain intervals, punctuate speech.

4) Pragmatic. It's got to follow all the regular Gricean rules. Relevance, etc...

I'm not a particularly adept curser. It was interesting to go to Spain for the first time and learn the rules there.