Why not choose a part of her body, any part, and then tell her why you love it? and then make your way along her body so you're communicating exactly how sexy you think she is, in every way and everywhere possible. Even places like her belly and arms, tell her all the good things about her body and she will feel very loved
If you want to make it dirtier, you could do the above and tell her what you want to do to it, ie suck/rub etc, or what you want her to do to you with it! Just a suggestion...