Welcome to the site. Because of the scope of experience of our members, you will find a variety of ways to accomplish almost any project. So let me stick in my 1 1/2 cents worth. I usually start with a length of wire, double it over, put the closed end in a vise. Then start twisting. Wherever you want a barb, insert a couple of pieces of wire 1/2" long. When you get the length you want, go back and twist the small pieces to make 4 barbs, then snip off the ends with wire cutters, which will give you a sharp, silver barb end.
Art