Start with 2 or 3 100% wool, knit sweaters (check the thrift stores). I chose a bright red, a gray and white, and a brown and mulitcolor. Moth holes are no problem for this project.
To felt the sweaters toss them in your washing machine on hot with detergent and run an extra cycle. Dry in the dryer. Repeat if necessary. The sweaters should be well shrunk and thick--they should not fray when you cut them.
In addition to the sweaters, you'll also need sharp scissors and a sewing machine. Ready to go?