People just don't swear like they used to. As long ago as 1944, H.L. Mencken, the great observer of American language, sadly noted that cursing had been on the decline since the Civil War, and that while there was still obscenity, "it is all based upon one or two four-letter words and their derivatives, and there is little true profanity in it."
Taboos against what we would today consider pretty mild exclamations like "damn!" "hell!" and "Jesus Christ!" led the swearers of years past to come up with creative substitutions that gave them some measure of emotional release while keeping within the bounds of propriety. These substitutions are called "minced oaths," and they've left their mark on our vocabulary. Gosh, gee, golly, dagnamit, darn, drat, gadzooks, zounds, heck, and cripes are all minced oaths that are still around to charm us with their innocent old-timey ring. But there are others you may not have heard of. They could come in handy when you get tired of ho-hum obscenity and want something with a little more profane zing.
A substitute for "by Jesus!" that is similar to "bejesus!" but jabbier. An Irish import, along the lines of "faith and begorrah!" Especially good for toe-stubbing.
A substitute for "goddamn." From an 1854 Dictionary of Northamptonshire words: "Consarn you! If you don't mind what you're about I'll give it to you!" Slow down and hit both syllables equally hard, and it's like squeezing a stress ball.
Another "goddamn" form. "Well, dad-sizzle it!" was one way to show you meant business. There were a whole range of "dad" forms, from "dadgum" to dad-blast, dad-seize, dad-rat, dad-swamp, and many more. This one sounds surprisingly modern, like something Snoop Dogg (Snoop Lion?) might come up with.
A substitute for "damnation," similar to "tarnation" and "botheration." WTF is so tired. Try "What in thunderation?" instead.
5. Great Horn Spoon!
Something you can swear by, used in a way similar to "by God!" It seems to have come from seafaring slang, and might refer to the Big Dipper. But you don't need to know the origin to find it useful. Today the strange randomness of the words makes it feel mystically satisfying to shout.
A shortening of "by God's nails!" This kind of shortening also gave us "zounds!" (God's wounds), "Gadzooks!" (God's hooks), "strewth!" (God's truth), and "ods bodikins!" (God's little body). If you yell it thinking of actual snails instead, it's less profane, but more adorable.
This one goes along with the rest of the "gosh all" family: goshamighty, gosh-all-hemlock, gosh all fish-hooks, etc. "Gosh all Potomac" is the earliest one attested in the Dictionary of American English on Historical Principles, and it's about time we brought it back.
8. G. Rover Cripes!
One of the minced oaths that approximate the sounds in "Jesus Christ!" it uses all the strategies found elsewhere: the "gee" sound (Gee! Jeepers! Jeez!), the middle name (Jesus H. Particular Christ!), and the "cr" sound (Crikey! Criminy! Cracky! Christmas!).
9. By St. Boogar and all the saints at the backside door of purgatory!
There is no St. Boogar. This is a line from Sterne's Tristram Shandy, considered by scholars to have a homoerotic subtext. Let it fly with pride!
10. By the double-barrelled jumping jiminetty!
It's too bad the tradition of productive, long "by the" swears has fallen out of fashion. You could load enough crazy-sounding nonsense on there to really scare your kids into cleaning their rooms.