Giving someone a suddenly itchy bumhole.
Making their nostril start whistling.
The ability to shift a single lock of someone's hair into an awkward position.
Making a floorboard squeak spontaneously.
Causing bouts of hiccups. Or farts.
Teleporting a small bubble of pee out of one's bladder to someplace else. Maybe to somewhere appropriate for pee to be deposited. Or maybe not.
Provoking cats to fits of abrupt psychopathic violence.
Provoking dogs to howl enthusiastically.
Making a person think they just smelled a whiff of something extremely odd.
Making food taste vaguely wrong.

In other words, for the goofy powers, think about the sorts of pranks people play on one another, or the things that happen to us that are annoying or spooky. If humans have magic, especially if it's just a little bit of magic, then they would totally use it in situations where they want to get a laugh, or to be petty without getting caught, or to get themselves out of trouble in a pinch. Everything ethically-dodgy that we do, those people would do, except with magic.