Do you speak Jive? If so, “Golly” is a nice all-purpose word. (from Airplane: a character says “shit” but it is subtitled “Golly”).
Sometimes I do let out a well-placed “Blast!” but it’s usually when I am faux-angry, in memory of my sweet mom who used it.
Just pick some random words in German. Most of it sounds like swearing.
Schmetterling! Brustwarze! Hauptbahnhof!
midden mist
Can’t improve on Walt Kelley: Rowrbazzle!
(ETA: Surprised that Post #30 doesn’t mention it. 
)
Since ‘determining’ (ie: deciding) that the ‘ugg/uck’ sound is the naughtiest sound around, I’ve taken to using ‘mugglesnuggler’/‘mugglesnuggling’ as my go-to non-swear.
I’d have thought most Harry Potter fans would understand that to mean being unduly affectionate to rather boring people.
As it happens, I’m reading a German crime story which is coming up with some interesting new words for me - how about
*Rotzlöffel *(it actually means an annoyingly know-it-all young person who is still wet behind the ears; literally translates as “snot-spoon”)
Korinthenkacker (means someone who gets up everyone’s nose by being obsessed with nitpicking and irrelevant details, and gets in the way of whatever it is you’re trying to do - the kind of boss who times your visits to the loo and keeps a mental note of every minute of lateness; literally translates as “raisin-crapper”)
Honest to Pete!
Jiminy Christmas!
Bugger! Although it’s actually more profane in the UK than it is here, so if you’re planning any overseas trips, be careful.
I’d say 'Godamnit!" Blasphemy charge is harder to prove… it could be Jewish, Islamic or Zorastrian as well as Christian. And with all those false idols, who can really be sure the god being blasphemed is real?
Now the hard-core thing is to figure out how to spell it right. But if it is just for spoken use I guess you get my idea.
I’ve recently been using “bugger” on this board a bit, in phrases like “buggered if I know”. Mostly because I feel like I’m getting away with something, and I’m a cheeky and naughty little boy about things like that.
“Oh, [nonreproductive sexual act, also called sodomy, usually referring to anal sex or bestiality] it!”
(Did the adults notice? Looks around. Nope. Tee-hee! Let’s go again.)
“Oh, [nonreproductive sexual act, also called sodomy, usually referring to anal sex or bestiality] it to heck!”
So, yeah, I know, I should probably just stop doing that.
(Also, it’s not really very nice to sodomites, is it? Heck, some of my best friends are sodomites. I should be more considerate.)
I like what Moone Boy says: “Oh balls!”