well I can tell you what I like, can't promise it'll work for your girl. from the experience I've had with guys going down on me, it takes time to perfect.

the girl has a HUGE part in her pleasure actually, she has to be really concentrated and into it, feeling totally comfortable with her partner. if you sense she's tense or not really into it, you can relax her by telling her how she tastes really good and how you love doing that to her. when her part of the deal is made - meaning, when she's fully calm and concentrated on her pleasure, then you could start getting physical.

personally, at first, I very much like the tease of kissing all around the area, it really builds it up nicely. after that I like it when everything is being licked at first, and then concentrated on my clit. i like it being sucked really hard, but thats just me. I don't like it when they're sticking their tongue in me exploring, it feels really odd and not quite right.

make sure you dont keep changing what you're doing, you oughtta concentrate on one thing that makes her feel good and keep it at, changing your rhythm until she cums. being all over the place the whole time is no good and will not make her cum, perhaps just feel good.

Anyway, I prefer his finger on my clit better, much more powerful and effective