I thought what this thread needs is some advice for beginners, since there are probly quite a few on these boards.
First, forget the upside down shit. Forget it.
2. Learn where the clitoris is and master it. This doesn't mean lick it as hard and as fast as you can! Women need different stimuli than men! (read that again!) Think slow and soft and repetitious and when you think you're going as slow and soft as you can, slow down some more.
3. Let her tell you what she wants. I don't mean in words, most women won't say what they want and that's okay. Watch for signs that what you are doing feels good to her ( or doesn't) watch for thrusting, pressure against your mouth or hand. Listen for breathing changes and moans or wimpers. Is her vagina getting wetter? Is her clitoris erect?
4.Don't just go down off the start. Foreplay, foreplay, foreplay! The longer you kiss and tease and caress the better you'll be in the end! Make love to her body parts before you make love to her. I've given my wife an orgasm kissing the back of her knee.
Have fun and good luck!