a) two strips of calico or craft cotton (mine were were 10" x 20") (FYI - To clue you as to how bad a craft addiciton I have, this was a piece of cotton I bought 15 years ago back in high school. I never dreamed, at age 18, that this would turn into a storage bag holder. Funny where life takes you...).
b) a hanger - child size are great
c) about 10" of elastic, give or take
1. Place your pieces right side together. Working with the end you ant to have as the top (one of the short ends) use pins and mark a one-inch opening in the center. Sew this edge together, stopping at your pins so that, when you press your seam open, you have an opening like this:
Forming the hook of the hanger into a loop will keep it on the cuphook and the swiveled design will allow the bag to move without falling while mounted to the ceiling.
So bend your hanger appripriately, then slip it into the bag and through the hole.