ok here is one method, you have to get a few ioi's at first, read her behaviour very carefully, see if she pays attention while talking to you, see if she touches her skin or rolls her hair around her finger, notice if she is comfortable to hold your hand and if these IOI's are there, you have a good chance, so there are different way of getting the kiss:
1. Ask her! seriously, it works, if she is not intrested, she'd say no, and you won't look like a tool and you won't get slapped (usually girls find it unusual if you ask tho), or she would reply "maybe" and you reply, "well , lets find out!" and lean forward for a kiss!
2. If you smoke and she does too, or at least she doesnt mind smoking, tell her you are going for a smoke and invite her along or see if she does come willingly, its easier to kiss a girl when her friends or yours are not watching!
3. In the middle of conversation, when you are talking and after she has "qualified" herself to you, just for 3 seconds, pause and just stare at her in the eye, if she smiles a lil, or she is nervous, or leans abit forward, go for a kiss!
4. texting games, tell her "Ever tried texting people who are sitting beside you? its th funniest Sh1t" and you send her a message "how you doing?" and you tell her, oh probably you'd slap me if you read that! She will most probably say "why what did you say?" she would mostly laugh, then she replies, then you say "come here often?" and watch her reaction, and wait for her response, and you finally send a message "how about a kiss?" and before she opens it, you say "you'd deff slap me for this one!" and you laugh and you will get one of the answers from the hint #1. (Believe it or not, that's how I got my current girlfriend to kiss me, with only text gaming)
please remember
Do not use too much tongue, just a lil and keep it short, and keep your hands off her ass, boobs and etc! If you keep it short, she will overcome her fear, as she has experinced it once with you and it was a safe one, she is more comfortable to do it again!
Good luck my brother in crime.