Play with continuity. Write a short story where things suddenly appear for no reason, are missing or keep appearing and disappearing randomly. If you have ever noticed a movie or television show where items seem to move or appear and disappear as if they have a will of their own you will know what a continuity error is, on film. We can make these kind of mistakes in writing too. No human can be kissing lip to lip while licking the base of her spine in a romantic scene, for instance. It's also pretty tough to hold him close, wrapping your arms around him while also unzipping his pants - we just don't traditionally have that third hand to work with. Though it's funny to read glitches like this in a make out scene, they can happen in any action you write.