Oral stimulation is great for many reasons, but it can be even more enjoyable when customized to a woman's needs and preferences. Knowing how to lick her anus, for example, can make her moan and even turn her on. And it's easier than you might think if you lubricate your finger with spit or a little lube before touching her anus.
For some women, licking around the opening of her vagina is very pleasurable and will trigger orgasms all by itself. But for others, you need to do more. One thing you can try is to tie her arms above her head and let her restrain herself a bit before you begin. This allows her to control the speed and pressure with which you lick her out, giving her more pleasure and control over the experience.
You can also tease her clitoris a bit before you start licking. The clitoris is sensitive and may need some gentle pressure to activate her. In addition, her clit can taste or smell different, depending on a variety of factors. For example, it might taste coppery or metallic, salty (from sweat), sour (from bacteria), and even tangy or fermented at times.
You might even suck on her clit a bit to add more sensations and increase her orgasm. However, you should be careful not to go too hard or fast at first because this can overwhelm her and cause her to shut down before she reaches her peak.