This is the way you're supposed to do it.

Make sure you're in the right mood.
If you go in for a kiss press your lips up against his/hers gently, then if you wanna.. gently start sliding your tongue in there mouth moving in different motions around the mouth, playing with tongue. If you want to be more intimate go in a faster, harder motion... sucking on the lips, gently biting, not just around the neck.. on the whole body. Even gently rubbing with your fingers on the back or arms very gently, giving them a goosebump feeling. Rub your fingers threw there hair... grasp them tighter when you like what they're doing or react back in a more aggressive way, it's a big turn on.