There are many ways to keep the ends of your lines from fraying, this video covers whipping.
Whipping is the act of tying the end of the line tightly with a small line to bind the strands of the line together.
This video shows you how to do it, start to finish, and some tricks that will help make your life easier.
Music:
“The Bottom (Instrumental)" by Josh Woodward. Free download: http://joshwoodward.com/