I like the idea that horns are made of keratin, because it allows for a lot of opportunities for kids doing weird things with them. Not sure how that would work, necessarily, with horn sensitivity? I like the “orange = horn, red = velvet, yellow = new growth” thing, but antlers have blood vessels through them: you could always say horns are a very thin layer of keratin with blood vessels over a sensory organ, and the sensitivity comes from that? IDK!
In any case, banding horns would be a terrible idea, kind of similar to corset piercings, except instead of rejection, you’re exposing the internal organelle, which may look super cool (blood-tinted bands!), but will probably result in you DYING OF INFECTION. But hey! You’ll stand out before then! Cutting back your horns has to be common practice, given that Tavros’s horn size seems note-worthy but not unusual, so maybe it’s a bit like waist training? You make six or seven cuts, training the organelle to recede, until you’ve either got them at the length you want, or else it’s as short as it’s going to get.
Horn painting is like glossing! Paint designs of your quadrants in them.
Do reverse-horn colours. Goth kids paint their horn-tips white for
conventions, people paint their horns white and do different designs for
theatre shows like kabuki, and painting your horns black was probably a big part of classical Greek theatre.
Stuff like filing, sanding, lacquering your horns with gloss are probably all really common, if expensive / time-consuming to do. Keeping your horns permanently bright and glossy is probably a hassle and something of a status symbol? “Look at how completely tough and awesome I am, that I can afford to make my horns a giant, shiny beacon for people to hit!”
Jewelery is probably the same thing. Neat to look at! Also alternatively a symbol of how tough you are, or how much of an easy target you’re going to be.