Women vary in the amount of direct stimulation they can take on their clitoris. Some women love it if you suck hard
on their exposed clit, others squirm in pain. You may encounter a woman who is unable to take direct stimulation of her clitoris.
You'll have to stimulate it indirectly, such as through her labia. Often, what is unacceptably rough at first may be fine
after she's very excited. Actually most women need a good bit of stimulation before they
are ready for stimulation of their clitoris, Once ready, that's where you want to devote your attention.