From my experience, I don't even say anything to the girl when I go down on her. We are making out, which leads to me fingering, then I decide to eat that box. Also, after a girl has given you a BJ is a good time to do it. Just say, "Let me return the favor" or something in those lines. Believe me, she won't resist. I love eating box, I once sat there eating this girl at a party's box for an hour which was way sweet. Concentrate on the clit most of the time of course, but also tease her. What this means is lick her ab region, the inside of her legs, and around the edges of her pussy. Trust me, this will get her way hot and once you do start munching the box shell be cumming pretty quick. Hope this helps, and good luck. You are in for the time of your life!