Here's a quick tutorial. Since I really suck at posting tutorials, (and I don't have pictures to go along) this will have to do for now. However, if you have any questions or want detailed instructions, please just let me know.
1. Cut out 3.5'' squares out of two coordinating fabrics. The amount of squares you cut depends on how large you want your holder to be.
2. Sew them together into rows, alternating squares until you have a flat piece of fabric.
3. With right sides together of the piece you just created, sew the thing together to form a tube. Turn right side out.
4. Attach a piece of elastic at the bottom to serve as the "exit" for the bags.
5. Fold down 1/2'' at the top and make a casing for your ribbon/thread to be put into. Thread this casing through with whatever you have decided to use as your hanger.
6. Hang up and load with your bags in the top!
I'm linking to these parties!