Unless we're writing for The Sheriff of Mayberry, we don't use dang or golly gee or durn it or
heck. We use f**k and d**n and other wondrous evocative words with good old Anglo Saxon fricatives. (by the way, it is the fricatives - the way the word feels in our mouth - that makes us like many of the old curse words)
Definition of FRICATIVE: a consonant characterized by frictional passage of the expired breath through a narrowing at some point in the vocal tractI realized on about my gazillionth revision, that the protagonist of my current novel doesn't really swear as much as I had her swearing. That would be me actually. I'm a big time swearer. This is true and I totally blame it on two things - my folks had a friend, a woman, who swore like a trooper, and they loved her though they didn't love her swearing. Somehow this made swearing very attractive to me. The other thing is the afore mentioned fricative - the way that most of the good old anglo-saxon words feel in the mouth - all rough and satisfying. Now, i'm not a goof and I'm not an adolescent. I know when and where to swear and I also know that I go there pretty easily - but not my protagonist. She isn't me and swearing wouldn't be her thing so...out came all those lovely words.
So, the heck is, that we have to use all our words appropriately - in the right place and at the right time.