The Mystery method kiss-close was one of the first things i learned. Even before i studied game.
When i wanna kiss a girl (that i obviously know is attracted to me), i make a yes ladder in conversation first. I try to get 3 YES answers from the girl in a row. So i'll ask stuff like "did you have as much fun as i did???" and stuff like that. Then, just stop whatever you are doing, "gaze deeply into their beautiful eyes" and ask "Would you like to kiss me?"
There are 3 ways for this to go down, and there's answers for all of them:
1. Yes. The rarest answer. When said, initiate French skills.
2. Maybe/I don't know... just say in a near-whisper voice with a bit of a smile "Well let's find out..." If she smiles, does something with her lips, or moves her head towards you, go for it tiger!
3. No. Just say "I didn't say you could, it just looked like you had something on your mind

" Then go back to regular conversation or game or w/e.