Since the bag is not necessarily beautiful to look at, we recruited an (80's style) model to show it off. Bicep curls, Skull crushers (triceps), Flys...
Step 2: Cut out a circle
First, fold the piece of fabric over in half. Next, we outlined a circle on the fabric using a pot cover. Our circle ended up having a diameter of 12 in. We found this fit our 5 lb. bag of rice quite well, though there was some extra space. We speculate that a 10 lb. bag could be stuffed in here.
Pin both halves of fabric together and cut out along the line.