Among many effective methods is the trick of repeatedly dragging the fantasy story back into the drearier aspects of what we generally think of as the “real world.” In the very worst example of that that I ever saw, the Elf turns to the Dwarf and says, “We must learn to respect a diversity of lifestyles.” I happen to know the author who wrote that. He’s a good guy. Otherwise he’d have to be put to sleep or something.
Having the characters in your fancy talk like modern teens’ text messages is guaranteed to ruin your fantasy. You’d be better off writing it in Rongo-Rongo script. Then at least we could maintain the untestable possibility that it might be good.