The placement of this piercing is very important. It goes through just the small amount of skin above the clitoris either vertically or horizontally. Vertical placement is generally more comfortable for the wearer and a bar or ring can be used. A bar is more comfortable - the length of the bar will need to allow for swelling and larger balls are preferable as the larger ball sits on the clitoris affording the wearer more feeling and as the skin is so soft smaller balls can work their way through the piercing as it stretches easily.
Careful measurement is needed and the piercer also needs to be aware with either horizontal or vertical where the ball of the barbell of ring will sit in relation to the clitoris. A horizontal one needs to be placed really straight and not too high or low. If you have a larger outer labia then the vertical placement is preferable to prevent discomfort from twisting.