There are a ton of good how to videos on making these things so I am not really going to go into that.
What can Para Cord be used for? - Used whole or gutted it has many uses, here are a few:
Added grip for knives and other handles
by Andrea Saia
by Chodaros Bling
by Maribel Duran
by Pembury Woods
by The Weavers of Eternity Paracord