Leaning in signals that you want to kiss the person, and tilting your head prevents you crushing your nose against the other person's.
Make sure your breath is minty fresh and clean. Naturally you practice good oral hygiene, but if you have any doubts about your breath, take a breath mint shortly before the kiss. Make sure to finish the mint or gum before you lock lips.
Be careful, as some mints may leave a bad aftertaste and make your breath worse. Water is the best bet! Leaves you no aftertaste, and freshens your mouth and does not leave you thirsty.
Approach the kiss with confidence. Try to kiss their cheek so they turn their head your way. Once you've chosen the right moment to kiss someone, there's no turning back, especially if it's your first time kissing that particular person. Be decisive and confident. If the person doesn't want the kiss, he or she will let you know, but until then, act as though you're a pro.
Set the mood. If you truly want your kiss to be passionate, you will need to set the right mood. That doesn’t mean that you have to throw rose petals everywhere and light a hundred candles, but you should be some place without many distractions--that way you can both focus on each other (and your passionate kiss).
Lean in and tilt your head slightly. Leaning in signals that you want to kiss the person, and tilting your head prevents you crushing your nose against the other person's.
Start slowly. Don't try to thrust your tongue into your partner's mouth right away. Simply press your lips against theirs. Close your eyes as you do to heighten the intimacy and to avoid looking at the pores on your partner's nose. Imagine your eyes are being controlled by a dimmer switch.
Let yourself linger between kisses. Kiss your partner once, slowly, letting it last for a few seconds. Then slowly draw your lips away, keeping them close enough to your partner’s lips so that they are almost touching (but aren’t). This lingering will help build the passion, and will really capture your partner’s full attention (as if you didn’t have it already).
Open your lips slightly. Once the kiss is accepted, try opening your lips slightly. If the other person follows suit, try slightly varying the openness of your lips (both more and less open) throughout the kiss. You may wish to explore the person's lips and tongue a bit with the tip of your tongue. There are no rules; just try to make your motions smooth.
Keep in mind that there is a thin line between passionate kissing and a drool fest. In order to gauge how wet your kisses should be, kiss the back of your hand like you would if you were kissing your partner and opening your lips slightly. You should leave a slight amount of moisture that dries up in a few seconds. If you see more than this, or leave a big wet circle on your hand, you’ve overdone it--dial it back.
Consider the French Kiss. As the kiss progresses, you may want to try French kissing, in which you insert your tongue lightly into your partner's mouth and let it dance with your partner's tongue.
Be sensually aggressive. After you’ve been kissing for a while, you should try getting a little more adventurous. In between kisses, gently bite your partner’s lower lip, letting your teeth graze their lip as you pull away. (Do not suck on their lip or bite too hard, unless they’re really into that).
Try some necking. If things are going well, consider spicing it up a bit by moving your head down to kiss and lightly nibble your partner's neck.
Keep your arms busy. You seldom, maybe never, see a great kiss in which the participants just let their arms dangle at their sides. At the very least, embrace your partner and gently pull him or her towards you. You can also run your hands through your partner's hair; or caress his or her back, sides, or other parts of the body. Wrapping your arms around your partner can also be a big turn on!
Where you put your hands should be determined by the status of your relationship, your desires, and your partner's signals, whether spoken or communicated non-verbally.