Educate yourself as to female anatomy.
learn to identify the clitoris and, more importantly, learn how to locate it with your tongue.
Each woman is different. Some like direct stimulation, rolling your tongue around it in a circular pattern.... some prefer stimulation a little high or low, some like a little flick, then a tiny pause, then a flick, then a tiny pause...
Try to zero in on the technique that seems to get the best response. ( encourage her to be vocal in letting you know what works for her)
At first the clit will get a little bigger, stiffer and easy to keep track of...
As she gets close to orgasm, most women's clits will suddenly get very soft...
this is where you are most likely to lose the little sucker and she will slip off the edge...
YOu need to keep up your technique, and increase intensity or frequency at this point, and try to stay on target....
You know you are there when the padded saftey thighs clamp down on either side of your head shake some sense into you.
For most women, immediately post orgasm is when they need you to lighten up or lay off for a half a minute.... keep the tongue working... but lightly over a wider area, avoid focus on the clit for 30 seconds or so and then begin to gradually zero back in on it... staying aware of her response. Build back up to another crescendo for a second orgasm... lighten up for a short bit then dive in for a third.
Some women like their asses kneaded, or, if you can reach, the breasts and or nipples caressed, tweaked, or gently mashed.
You will find the first orgasm takes the longest, but that each successive orgasm is quicker. Some women are okay with the 'refractory lull' getting briefer between orgasms... sometimes to the point of continuous full on orgasm on orgasm.
If you can get a woman into this state of steady rolling orgasm, and keep her there for 15 or 20 minutes... she can get into a semi delirious state where she will achieve orgasm from almost any rhythmic stimulus. A good pounding fuck, or if she's the type, even a spanking, can result in body shaking orgasms.
Some women can't take the continuous stimulation and prefer discrete orgasms with a slight lull between... whatever works for her, your job is to satisfy her needs...
But, honestly... ANY willing woman can achieve 20 to 50 orgasms in an hour or two if you pay the right attention to the right things.
And a GOOD man makes sure she gets 20 for every one he has.
Leave them dizzy, disoriented, and disproportionately happy... and they will come back for more.