This has definitely been done before (hence where my idea came from) so I claim no proprietary rights for this idea and promise not sue anyone for patent infringement if and when you copy me.
Gather your supplies:
Glass Christmas Ornaments (any size)
Yarn (any color, I went for the color I wanted in the cheapest brand I could find)
Note: You don't have to use clear glass ornaments, you can really use just about anything. Racquetballs or ping pong balls would work wonderfully as well.
Step 1: Take off the thingy at the top of the ornament.
Please excuse the pictures. My camera all of the sudden takes crap pictures. Apparently my iPhone does a better job. Me not happy.