I learned to do amazing things using my hands. Some secrets:
1. Touch her clitoris gently but repeatedly about twice a second. This will help her reach the right level of arousal. You'll know this happens when you feel her hips starts to squirm.
2. There is a spot on the roof of her vagina (the surface further forward) where the clitoris widens. It's usually just slightly less than an inch in, but you'll have to explore (part of the fun). You'll know it because of the pleasure she has when you touch it gently. When you find this spot, continue to touch it rhythmically, while you're attuned to her movements and the sounds she's making. From those you'll be able to tell if you're doing it properly or if you need to adjust. While you're doing this, it helps to be using the rest of your body to make the rest of hers feel good. A tongue laterally across a nipple, or even just gentle kisses across her ear and the side of her neck can help the mood along. Cheeks and lips are sensitive too, but keep moving, and keep her guessing where you'll go next.
3. Have patience. Female orgasms are hard to reach, and she'll need to bring herself there. All you're doing is providing the motivation, by giving her a lot to be aroused about.
4. When she finally climaxes, imagine you can feel the waves of pleasure washing over your body as well.
I don't think anyone came away from that experience dissatisfied.
Good luck. I hope it helps.