The most amusing I’ve heard was “Jebem ti supu od Isusovih kostiju”-“I’m fucking your soup made of Jesus’ bones” (said by a Serb from former RSK), looks to weird in English. Interesting ones for me are “Jebem ti sve po spisku”-“I’m fucking everybody on your list” (meaning everybody related to you) or “Jebem ti sve žensko”-“I’m fucking everybody female of yours”. I’m trying to reduce swearing to a bare minimum, but I mostly use “jebiga”-fuck/ fuck it (literally means fuck him-jebi ga), “jebote”-fuck (literally fucked you-jeb’o te) “koji kurac…”-What/Why the fuck (literally which dick/for which dick), just “kurac”-dick as a negation and regular “Jebem ti _____!”-Fuck your [feel the blank]. All those mentions of mothers are pretty common. Although I like to make them nice, like “opštim ti s majkom” or “jebem ti ženskog roditelja”