Using a coping saw blade removed from its saw body, cut the general outline of the slingshot from the foam block. I learned that when doing this, try to cut bigger than the outline so there will be more room for error and filing. After you have the rough shape cut out, take a woodworking file and file it exactly how you want the finished slingshot to look (pics 2 & 3). Make sure that this is precisely the shape you want in the end, because it is much easier to file Styrofoam than it is to file aluminum.