A great way to use up yarn (+ decorative threads)- is to use a small butterfly board loom or larger peg looms.
A really easy technique and very easy to do.
wind the thread, secure the cross points, lift off the loops and join the squares of smaller pieces
Basic Tutorial for the butterfly Loom
Butterfly Looms - Different Sizes All sorts of patterns and creative options around for different designs and projects on you tube and pinterest
And here's a
3 video tutorial on how to make a pompom effect by Anne Russell using a large peg loom. Good tip about the gloves and very clear demo of how to make the tie knots more secure.