Attraction is a funny thing, and it most often has nothing to do with physical appearance - although being well-groomed is always important. Women - and men too - are attracted by happy, confident others. As a guy, we notice the girls dancing and having a good time with their friends. We notice because they appear happy!
Girls are the same. If you appear to be happy and confident, and excited about who YOU are - others will be drawn to you. I once entered a bar in LA at about 2 pm on a weekday. There were 5 people in the bar - all sitting separately except 2 ladies at a table. My friend told the bartender that I could juggle 5 limes. That's right "juggle!" And so I had to prove it and did. The bartender applauded, we got free drinks, and within minutes everyone, including the two ladies, were at the bar with us. Why? Oh it had nothing to do with the juggling; it had merely to do with the fact that my friend and I - by juggling - appeared happy (I mean sad people just don't juggle).
Another time, and very unlike myself, i entered a bar dancing with two guy work buddies (actually doing a kick line like some chorus girls!) Laugh, but let me tell you, within minutes, a lady approached and said to me: "I hope your not leaving soon. But if you are, I want to go with you!"
And I once went on a cruise and met women WITHOUT coming out of my cabin! I merely opened the door slightly, put on some music, lit some incense, and had my own private party. Almost every lady (and guy) who passed by would stop and inquire "Hey, why wasn't I invited?"
The attraction in each case came from giving the appearance that I was happy (even while alone!)
In a bar or at a party or at the damned museum, you can do this simply by laughing in conversation with a friend or smiling when you make eye contact with a lady. (Conversely, sitting at the bar and looking "cool" seldom works.)
Want to be attractive - be happy. Happiness then attracts others and the fact that others are attracted to you will bring even more people to you because when they see you are "popular" you become even more attractive. This is why it is important when going out alone that youas a guy speak to the other guys in the bar or at the party. The girls will notice that you are the man - the one who is confident and in control and happy, and having the guys like you will make you appear more attractive to the girls.
So, 1. Be well-groomed; 2. Appear to be happy and confident (not cocky); and 3. Make friends with the other guys. Afterall, all the technique in the world is useless unless you at first attract.