Bicycle cable ends are available from you local bike shop, and online. They crimp on to prevent the cable end from fraying. I prefer using a plastic bead, like the kind associated with Mardi Gras.
Tools & supplies: Plastic beads, small butane torch (a butane lighter will do in a pinch), good wire cutter (preferably a bicycle specific one).
1. cut cable, so end is not frayed.
2. heat end of cable till it turns red.
3. slide/ melt the bead on.