precise). hold the pin upright and try to get a little hot glue to run down inside along the inner wall to make the clay stay in better. use the eraser end of a pencil (i used a spare crystal) to shove the clay into the inside of the pin. don't get the clay too near to the top because more glue is going there.
once the clay is inside arrange your objects in the pin, the clay will get dents in it where you want them to go. then take the objects out. put a layer of hot glue over the clay, making sure the glue touches the inner wall 