1. Several varieties of dried beans are needed, just test them first to see they are not thicker than the CD case before you start to glue. With a standard CD case open and the tray removed, I used a flat brush to spread a generous line of Mod Podge around the outside edge of the case. I lined up one row of beans on this, pushing them against the lip to make a straight line. The 1/2" or so where the spine used to be needs to be left clear though as the front of the case will not cover it up when closed.
2. After the outside row was complete, I painted another line of glue inside it, and lined up another row of beans. I found that this process of working from the outside in really seemed to help control all these wiggly little round shapes. I made a total of four rows or rectangles before I just filled in the remaining center with glue and the smallest beans.