Shift and brake cables can be finished after they’re cut in a few ways. There’s the "let it explode into rusty tiny threads that love to get between your fingernails and finger" method, which, perhaps unsurprisingly, is my least favorite method. There’s the norm-core way to go, with a cable end crimp mushed into place. Effective, but probably a 5/10 on the looks department. Grant Petersen’s advice is to coat the cable with beeswax before you cut it, so when you cut it, it doesn’t fray. This works fine, as does his follow up advice to stick a biggish glob of bee’s wax on the cable end after it’s cut. Looks like a misplaced booger, but works without issue. Back in the 70’s, discerning bike shops soldered the end of cables, but you need a really powerful soldering gun, and patience for this. Looks ok, clean, but also like there is something missing.
Easily the nicest looking and easiest to use cable finishing program is the Forager Cycles Cable Cherry. It’s not the cheapest, and doesn’t come in hot neon green (yet) but if you want a standard color, and want the finest cable ender out there, this is that. They come in a pair, so most bikes will need 2-3 of these, depending on how many cable ends you have. Canti brake bikes, or center pull brake bikes that also have two derailleurs need 3 pairs. They come in a cute little box with a small hex wrench for install. You’d be hard pressed to strip the cherry with the tiny tool, but don’t go all Hulk Hogan circa 1987 on it. US made. Anodized aluminum.