Tongue, and lots of it! You want your tongue to hit her lips before your lips do. Think of it like having sex on your face, and your tongue is the penis penetrating the vagina that is her mouth.
Keep your eyes open the entire time. Eye contact is important! If she's closing her eyes, she's bored. If that happens, more tongue!
For bonus points, start kissing around her lips. Or what I like to do for the high score: use your tongue to draw a heart on her face (from the chin to the forehead).
Breathe through your mouth ONLY!!!! Girls don't want to feel your nosebreath on their face. Take a deep breath and exhale into her mouth for extra points.
Later on, try sucking on her tongue. Experiment to find out how hard you can do it without making her tongue bleed.