So clip-on earrings aren't exactly "on-trend" as far as I know, but ever since my earlobe ripped (it's pretty gnarly and I'm strangely proud of it), I've had to acquire an appreciation for them-- which wasn't difficult! The thing about clip-on earrings is that many of them--especially vintage ones--are like little brooches for your ears. They're often much prettier and more intricate than regular earrings, they're unique, and they stand out more. At the same time, they're also more pull off-able than say, statement necklaces (looking at you, weird bib things).
Affordable vintage clip-on earrings aren't always easy to come by in the real world (I've found that even just costume clip-ons will run you $25-$45 at city flea markets and vintage stores, but it's easy to trick yourself into buying them because they're so beautiful), but at thrift shops and on Etsy, rad clip-ons abound for under $15. (At thrift shops, more like under $2.) I usually don't bother looking for new ones because they're either way tacky (sorry J. Lo), or way too expensive--and so few regular retail stores stock them.
Here are some fun clip-ons that the internetz has to offer for under $30:
$18- LemonTreeVintage, Etsy
$22- brenhann, Etsy
$2.99- RibbonsEdge, Etsy
$27- Loveoldstuff Costume Jewelry, Ruby Plaza
$20- vintagesparkles, Etsy
$9.99- Angel Mountain Group, Amazon
$15- NotYourSloppySeconds, Etsy