I have made it my goal to stop cursing. Not only is it impolite, but it's something you can't turn on or off. You have to stop completely if you want to make sure the words do not slip from your mouth. Whether at work, over the radio, or around new people, you don't want to be caught off guard. Additionally, using curse words can often obscure our thoughts, attaching a strong emotion to something without actually describing what is happening.
Getting Caught
When you're in the habit of cursing, you will get caught. No question about it. At work, at prayer, in public, meeting new people... You don't want that to happen. The best policy on cursing is simply to stop.
Mental Clarity
Using curse words can often interfere with your clarity of thought. Instead of using a curse word, try actually describing what it is that is troubling you. Don't just use minced oaths like "oh hamburgers." Say something meaningful, or replace the phrase: "Oh no!"
Substitute Words
In place of "oh, shit," say "oh, no."
In place of "what the fuck," say "what on earth?"
In place of "fuck" or "dammit," use other interjections like "agh!"
Take a tip from Cee Lo Green. In place of "Fuck You," say "Forget You."
If any other replacement for the ef word fails, you could use a variation of "wretch," so that "fucking" would become "wretched" or "wretchedly."
When something is "the shit," just say it's "the stuff" or "the good stuff." By extension, a lot of instances of "shit" can be replaced by "stuff." Think "and stuff" and "that stuff" rather than "and shit" and "that shit."
George Carlin said "fuck the fucking fuckers." To be more descriptive and less profane, and suitable for radio, we can say "forget the stupid losers."
For sexual acts, we can use other words besides "fuck." We can simply say "do me" or "take me." If that's not strong enough, you could say "plow" or "conquer."
Instead of "cock," you can just say "thing" or "junk." Instead of "pussy," you can say "cooch." If using "pussy" to refer to a person, you can simply say "wimp;" it's more descriptive, anyway.
Remove the Word
In place of "pain in the ass," just say "pain" or "huge pain."
In place of "what the fuck," just say "what?!"
Use Adjectives
Sad, awful, terrible, painful.