Start with very gentle kisses. Ask your partner to concentrate on the lips that have not been pierced, in the beginning.
Check with your partner whether you are hurting him with the ring or stud in your piercing. If you are, adjust your position so that the stud or ring doesn't make contact with his lips or skin.
Encourage your partner to use her tongue, and ask her to gently brush her tongue around the piercing, without pulling or catching it. This can be very sensuous and make the most of the piercing.
Open your mouth and use your tongue, if your piercing is on the bottom lip. This should not affect an open-mouthed kiss, unless you have a stud or ring that sticks out and could scrape your partner.
Experiment and make it fun; trying new things will make the kissing more exciting. Agree to tell each other if anything hurts, and kissing should remain enjoyable.