Lol I take the piss mainly. It's a good way to find someone who's suited to my personality. Some guys don't like it.. but that means that I won't get on with them in general because I'm generally loud and quick-witted.. and some guys find that intimidating because they generally like 'quiet nice girls'. And then they find when they're in a relationship with them.. they are generally not fun and whine and cry about a lot of things. I know a few girls like that.. particularly one.. who everyone is attracted to.. but all those guys who've been in a relationship with her get fed up of her overly emotional personality.
Good old fashioned ways to flirt are like playing with your hair (obviously if you're a girl), batting your eyelids.. laughing at everything they say.. even if they aren't funny or interesting. But those are all.. flirting techniques when you aren't in a relationship with a person.
If you are in a relationship with someone.. you can get away with most things.. grasping their crotch in public places.. putting your tits in their face.. answering the door to them wearing next to nothing.. text them with dirrrrrrty stuff.. have a physical play fight before you have sex.. that's a fun one.