I don't know how the frog closure got its name because it certainly doesn't look like a frog to me.  With it's elegant loops, it seems it should have a fancy name to match, like swirly closure or something.  Regardless, of its name, the look of the frog closure will surely add an upscale look to any of your garments and they're actually pretty easy to attach.  In this tutorial, I show you how to do it by hand and also by sewing machine.  You can pick the one that works best for you.  I, personally, prefer to do them by hand and to use the decorative rayon thread so that it matches the sheen of my particular frog closure.  These types of closures do not need to be only relegated to costumes especially when you're looking to give your garment an extra special look.