I make these all the time, so I've got it down to a science. The ideal mix is 1 cake mix, 1/2 container of frosting, and 1.5 bags of the chocolate melting wafers. I use a stand mixer to combine the crumbled cake with the frosting. I don't worry about letting it cool too much. I just let it cool until I can handle it. I also use a melon scooper to shape the cake balls; the small side makes 100 balls per cake mix. To dip them, I bought the cheapo chocolate dipping tool from the craft store, and it works fabulously. We made 400 of these as part of a cake table for our wedding, and they were such a big hit, people were taking them home by the handful. I also bring them to every faculty potluck at the school where I teach.