Oh wow... that was freakin hillarious!! >.< hehehe...MiracleOfSound said:Indeed.
It's a sidequest that boosts your stats for the main questline.
(nerdiest metaphor ever)
Seriously though...
I interpret flirting to mean behaviour in order to woo/charm/interest the opposite sex.
One of the greatest bits of advice I can offer in regards to wooing women would be to ASK. Ask what they do for a living, what they enjoy doing in their spare time, what they did on the weekend, whatever. Let THEM talk, and pay attention. Genuine attention is extremely flattering, and it lets you get to know her better. If you're finding yourself having to feign attention at her responses, then that's a pretty good indicator that you're just not right for each other. This form of flirting is extremely subtle and can be used as more of an icebreaker.
In my rulebook, pick-up lines are a big no-no. Don't go there unless you enjoy instant rejection. They just don't work! The message it sends to the female recipient is that they're only sexually attracted to you and that you have a set purpose - not a good idea.
I disagree with an earlier post that suggested it's best to start with flirting or sexual behaviour - it generally makes the flirter appear extremely sexualised and the flirtee extremely uncomfortable. Gradual progression is much less confronting - a casual compliment about her eyes, hair, skin or even clothes or jewellery (and I stress casual here. Don't overemphasise it or it seems creepy. Just something simple like 'your hair really suits you like that' or 'you have really nice brown/blue/green/grey etc eyes' will often do the trick.
As it's been mentioned previously, BE YOURSELF. No point in securing a date/girlfriend by acting completely different to who you are, then once you grow comfortable around her let your façade down. Just don't.
Touching isn't necessary in the flirting stage, but if you don't like touching, do you really want a girlfriend? All that holding hands and cuddling and maybe even kissing... AAAH!
Best of luck though