Dirty talk is a must. My particular favorites, in no particular order, include: cum for me baby, i want to devour that sweet little body of yours, do you like that, does that feel good, do you want me to fuck you, tell me you want me to fuck you, i love being inside you, i love the way you taste, do you like my cock in your mouth, your pussy tastes incredible, do you like watching it go in and out, oh my god you are going to make me cum, fuck me, take all of my cock.
Those are a few that come to mind. Usually that along with whatever else narration I feel is necessary.