I used that title because I'm aware that the terms "vaginal piercing" and "vagina piercing" are commonly used to search for information on this topic. However, this isn't entirely accurate and if you want to learn why not, please see this other blog post.

I know that the term "clit piercing" is also commonly searched, but actual clitoral glans piercing—of the clitoris itself—is very rare. It is piercings of the clitoral hood that are the most common. This is the skin above and surrounding the clitoris, which is not nearly as sensitive to get pierced, and to which far more women are anatomically suited. That said, if you're built for the piercing and brave, it can definitely increase the sensitivity and add to sexual pleasure and satisfaction.

I do offer professional anatomy consultations if you want to know which female genital piercing(s) you're suited to wear.

The number one female genital piercing for adding sexual pleasure is the vertical clitoral hood (VCH) piercing. The piercing is placed so that the jewelry rests on top of (and touches) the clitoris. Female anatomy varies considerably, but most are built with a hood that covers the clitoris partially or completely. Therefore, for direct stimulation to take place, the hood needs to be pulled back to expose the clitoris. But when jewelry is in a properly placed VCH piercing, resting underneath the hood, it allows for more direct clitoral stimulation without manual intervention. 

Some women find that this addition is enough to push them over into an orgasmic state during intercourse, though they otherwise require additional clitoral attention.

The number two female genital piercing for added stimulation during sex is the triangle piercing. Based on the requests I receive, it would be the most popular, but fewer women are anatomically built for this piercing option. While the VCH adds stimulation from the front of the clitoris, the triangle adds it from behind the clitoral shaft. The best way I can find to describe the type of sensation is to relate it to how it feels when a woman grinds this area against something or someone. What feels good is the clitoris pressing against the pubic bone. But with a triangle, you can achieve that same type of feeling without pressing nearly as hard!

I've had women with primary anorgasmia (never had an orgasm) who've had success as a result of both of these piercings! The women had their same partners and were engaging in the same sexual activities, so the only altered factor was the piercings. That has been incredibly validating to my life's work!

For maximum sexual stimulation from female piercings, you can wear both VCH and triangle piercings—if you're anatomically suited. As I describe in The Piercing Bible, this creates the "tantalizing clitoris sandwich" with jewelry surrounding it, both front and back.

Orgasm Machine?
No; to allay concerns, or hopes, such clitoral hood piercings aren't going to be continuously stimulating while you're trying to do your grocery shopping or focus on work. But you can expect these types of hood piercings (often called "vaginal piercings") to add sensation during sexual activities. Some women also find certain gym equipment or exercise a little more sensational too, when the piercing is still in its initial healing stages.  

This excellent resource on SchoolofSquirt.com can help make sure that your partner is well informed and knowledgeable about effective techniques for clitoral stimulation (whether you have a piercing or not).

Runners up: On certain builds, the horizontal clitoral hood (HCH) piercing can add stimulation when the bead, ball, gem, or other ornament on a ring touches the clitoris. But this requires a build with some of the clitoral glans exposed, among other anatomical considerations, and most women simply aren't formed that way.

There's also potentially added sensation with outer labia piercings if they're placed adjacent the hood so that the ball(s) on barbell(s) touch the clitoris from the sides.

No piercer can make any guarantees, but if you're seeking added sensation and anatomically suited and interested in female genital piercing, then it is certainly worth a try!