For my first instructable, I'm going to show a trick that never gets old. Reusing Yarn is easy, and you only have to sacrifise your old ugly sweater. You do this with an awl or a sharp knife. And patience...
Step 1: Think About Stuff
1. Obviously, before you destroy your sweater you should check if someone else wants it.
2. The bigger the yarn is, the easier it is to pull apart.
3. It's harder to pull apart a sweater that has several yarns in it. You should choose a simple sweater with one colour, without patterns.
The sweater on the picture is your ideal! One-coloured, big yarn, and unloved!