I'm not a person who straightly saying phrases in an extreme speed but I do have habit to say it. When I want to swear, I tend to vacant for a moment and say one from these three:

1. 'm sorry  "Ah, shit !" huffing first then rolling my eyes ;
2. "What the..?!" furrowing;
   
3. and a local phrase: "Cape, deh..." (literaly meaning: I'm tired. Used when you hear or see stupidity or repeated foolishness that makes you 'tired' by it ).