Here is what you need.
Fat Eight- 9x22 fabric
Iron on pellon
Start by cutting (2) 9x5 inch pieces.
Cut from the 9x5 3 inches off the top. Giving you (2) 6x5 rectangles and (2) 3 x 5 rectangles.
Fold over 1/8th inch along the longs side of the 3x5 inch pieces.
Stitch them into place.
Pin your small rectangles to each end of your large rectangles. Matching up corners.
Pin the second large rectangle on top of the first. Stitch around the outside edge leaving an opening along one short end.
Turn right sides out. Be sure to push corners out. Press.
Pin hair elastic to the center of the card holder. Top stitch around the outside edge of the holder. Be sure to back stitch over the elastic.
Mark where you want your button to go and hand stitch it into place.
Here are a few more projects you can do with a fat eighth
Camera lens cap holder by: Peta Pixel
Tissue Pouch by: Craft me Not
Gadget Pouch by: Made by Petchy
Chapstick holder by: Madelynerush