By Laura Snyder

As any one who's been on the receiving end of a very good - or very bad - smooch knows, a kiss can change everything. It can have the spine-tingling, firework-setting magic that makes you wonder if it will be your last first-kiss, or it can have all the charm of making out with a mackerel.

If you'd like to increase the chances of it being the former and not the latter, start here first.

Chemistry Lesson #1: Time It Right

Great kissers seem to intuit the precisely right moment to make their move. They know when to exploit our longing by barely brushing their lips against ours, and when to boldly capture our mouths with their own. Even if you're not genetically blessed with a good sense of timing, you can get a grasp on how and when to proceed by tuning in to you partner's body language and breathing. Time and conversation stops, your eyes lock, and the rest of the world melts away.

Chemistry Lesson #2: Get an Eyeful.

Okay, so no one likes a wide-eyed, deep pore examination during a lip lock. But a little self-voyeurism can be super sexy. According to the Journal of Research in Personality, a couple with their eyes locked on one another experiences a marked increase in feelings of passionate love. Eye contact going into the kiss establishes the moment and creates anticipation. But that doesn't mean you should stop there. Open your peepers just a bit for a quick peek at the action. You'll remember it better that way.

Chemistry Lesson #3: Take a Deep Breath

One of the theories on history of kissing is that it evolved from partners sniffing each other. Our noses are much more important sexual organs than we figured. Subliminal scents - or pheromones - play a major role in why and who we love and even dictates how often we have sex. So inhale your partner's scent while you're so close.

Chemistry Lesson #4: Always Leave 'Em Wanting More

It's just good manners to smile after a kiss, even if it was less than perfect. But if your smooch was smashing, don't pull away too quickly. You'll miss the only thing better sharing one perfect kiss - sharing more!