Give the Girl the Finger
I'm not big on techniques, blah blah blah-- but there's some techniques that screen naturally and avoid any traces of Mr. Funny Man.
This is one.
This is best for nightclubs.
If you see hot girl, lock eyes with her, smile/smirk, then give her the middle finger.
If she's cool, she'll play along and probably give you the finger back (or she'll shake her head and smile).
This is what we call "flirting," dirtbag flirting.
If she sucks (or is unavailable), she won't.
I've used this technique a lot of times, and yes- super hot girls get into it. They don't get this very often and they tend to know it's a joke moreso than average girls.
If the girl plays along, give her 2 middle fingers and shake your head sarcastically "yeah... you're cool."
Eventually just walk up to the girl (or motion her to come over) and talk to her.
You can say, "you still talking shit?" "whats your problem buddy?" or "you shouldn't be giving people the finger, that's so disrespectful."
Obviously this technique isn't going to land EVERY girl, it's not supposed to. You are almost guaranteed to land a fun girl with this technique though. No uptight sour nonsexual bitches! So just use it on hot girls, and you'll land hot, fun girls. That's the type of chick that I look for and this definitely works.
Feel free to stand in the same exact spot giving girls the finger for as long as it takes to get a decent response. If you go 0 for 10, loosen up, smile more.
if you don't want to give the finger you can give the [good looking] "loser" sign by making an 'L' with your right hand and putting it on your forehead.