As we've shown in our other tutorials, cutting and replacing the brake cable system on your bike isn't that hard of a process. That being said, one thing we always preach is 'repair before replace' and if your brake cables simply happened to be frayed on the end, they can be fixed easily. It is important to tend to the frayed cables early though because if they aren't repaired the problem can escalate where a full replacement is necessary.
The Twist & Cap Method
The frayed ends of a brake cable can be sharp, eventually fray more, and simply just look tacky. The thing is they still work just fine so it's best to tighten up this blemish. Take the frayed wires and twist them like you'd do with a bread tie. Once the wires are as tight as can be as close to the end take a wire cutters and snip a bit off the end to make a flush cut. Next take a wire cap and put it on the end of the once-frayed cables. Use a pliers to smash the ends of the cap so it doesn't move and you've restored order to your brake cables in a matter of seconds.