Some possibly useful food for thought...

[Aminar]

The best advice I can think of is to juxtapose two wildly opposite things, like something mythically awesome and hopelessly mundane. 
Something like:   "How in the name of Zeus's Butthole-"  Nick Cage, The Rock.  The best one I think Ive  come up with personally was "Christ on a stick!" because it is both literally true by the crucifixion, but also conjures a more "corndog" image than you usually see with religion. 

Another interesting example was the Dragonrders of Pern books, which didnt have much in the way of religion, so they pulled from teh distant history that was on its way to becoming myth.  They'd say "By the shell of the First Egg" or similar (a reference to the genetic creation of dragons as protectors from a unique and repetitive natural disaster), but often just shorten it to "Shells"

Yeah.  I like the juxtaposition thing.  The bigger issue is that I've made my own world to write in.  That removes alot of our own evident symbolism.  I always felt "Shells" was silly sounding.  I know within the world it has meaning, but that meaning had to be declared.  Having to buildup all of the needed profanity for an uncouth character would take chapters of backstory with meaningless dialogue and It's frustrating...

[The Deposed King]

Yeah.  I like the juxtaposition thing.  The bigger issue is that I've made my own world to write in.  That removes alot of our own evident symbolism.  I always felt "Shells" was silly sounding.  I know within the world it has meaning, but that meaning had to be declared.  Having to buildup all of the needed profanity for an uncouth character would take chapters of backstory with meaningless dialogue and It's frustrating...

I can see that.  On the other hand, my Chief engineer started using my color language from the first or second time we saw him and continued to light up a blue streak every time he entered the stage.  I think its all in how you sell it.

But again everyone is different, do what works for you.


You know now that I'm thinking about it, I had this other book, half written and not finished where they were always talking about 'putting down' slothful dishonorable people.  And by putting down I mean kill.  Connotations of putting down a wild animal or rabid dog etc.

It was really fun to write.



The Deposed King

[the neurovore of Zur-En-Aargh]

Profanity depends on the context you're writing in, like most other things - one of the things that struck me when I lived in Heidelberg was how much less severe scatological swearing appeared to be, compared to my defaults in England and Ireland, and how much more shocking religious swearing was to people. One of the more impressive fictional examples I've read is Ira Levin's This Perfect Day, in which contemporary sexual swearwords are totally lacking in shock-significance in context, but "fight" and "hate" count as truly foul language, and Levin makes it work.  Not an easy thing to build up the right sort of context for something fictional to have impact, but sometimes you can leverage that the other way around - have what people use as an expletive be a clue as to what is most taboo or repellent to that culture when it's not the same as the reader's.

[Quantus]

Yeah.  I like the juxtaposition thing.  The bigger issue is that I've made my own world to write in.  That removes alot of our own evident symbolism.  I always felt "Shells" was silly sounding.  I know within the world it has meaning, but that meaning had to be declared.  Having to buildup all of the needed profanity for an uncouth character would take chapters of backstory with meaningless dialogue and It's frustrating...

It doesnt necessarily have to be too specific, depending on how different your world is from common models.  "By the Queen's Chamberpot" could work, or "Son of a ____" fits with nearly anything that is contextually unflattering, regardless of whether it is something the reader new of (insert jabberwok or similar and it still works by the context).  Heck, "Crows!" from CA worked fine, and it appeared long before the cultural significant of crows predicting battlefield locations was introduced.  Its like Neuro said, using it as the curse word can actually give it the impact it needs by the context, rather than having to have it established ahead of time.