In a kissing context - Tease like a mother fucker! make it so she wants to explore with her tongue or at least naturally build to it - not like she is doing you a favour, but remember this aint blitzkrieg!!
TEASE TEASE TEASE! Kiss her on her lips, when she trys to kiss you back pull away and smile with a cheeky grin, come in, come out! really rev her engine, lightly brush her lips with yours but dont kiss.
Get as close to her lips without touching, try keep a sly/cheeky half smile going while looking into her eyes and tilting your head like your about to come in but you dont.
Feed her only tid bits, keep doing this at some point in this tease/kiss er... escalation run your tongue in the same teasing fashion along her lips then pull away every so slightly, keep your mouth sightly open and inviting and repeat the same brief action on your lips, she should start copying reciprocating, if she doesnt work it into your kissing variations and she will eventually, at some point the kiss will then transition into a full french: typically when you both try lick each others lips and you start tentatively exploring each others tongue

, just remember to vary the intensity, passion and speed - think rollercoster not a highway!
What your doing is building using your tongue into your kissing in a non explosive manner IE sticking it straight in(you dont walk upto a random girl and start fingering her right away lol .. well some might haha), your getting her excited then naturally building to that point.
While doing all the above you should still be trying to include additional physical contact, I like erotically handling the side/back of their necks varying a firm grip to a light touch, or an earlobe! infact any non normally considered erotic location or in proximity to said location it is great like running your finger down her throat between the breasts but not touching works a treat. Or tracing your fingers from her bum up her spine can get them shivering in excitement, gasping or moaning
The idea is to be a buffet of kissablity, not a farking washing machine with one setting! hope this helps!
