You will need:
2 rectangles of fabric (I use fleece and a print) decide how wide you want the opening to be, and double that measurement for the width of the rectangle. Decide how deep you want the bag to be. That (plus an inch or so) will be your length.
EITHER a strip of 1" foam OR a strip of boning, an inch shorter than the longer measurement of your rectangle.
Sew the foam (or boning) to the wrong side of your print fabric, a few inches from the long side.
Fold each rectangle, seperately, in half, right sides together, and sew down the side. I use a straight stitch, and then reinforce with a zig-zag.
Turn the print right side out, and put it inside the fleece tube. Align the seams, and sew around the end closest to the boning/foam strip.
