Hello Tal! I have the same problem myself. But I've figured it out eventually. First, you have to consider your audience. You have to ask yourself: Will it be for children 9-12 years old? Or will it be for teens? Of course, teens could handle swearing more (not that it's appropriate for children). If you're having second thoughts with the swearing, or when you think your character has said enough inappropriate words, just use, "He cursed." Or she cursed. You really don't have to mention it!
“I believe in Christianity as I believe that the sun has risen: not only because I see it, but because by it I see everything else.”
You really don't have to mention it! 
