As with everything, practice makes perfect, but these are some of the attitudes such successful people have.
1. When I meet a girl I am Interested in I will pursue but the outcome is not really important since there are always tons of choices.
She is not the only hot girl out there. Start thinking she is, and becoming timid that you might lose her, and guess what Einstein, you will. Don't overstep your bounds, move on when its not working, and don't care about the outcome and you will come off as not being desperate.
One End - This girl is my one and only, I cant blow this chance!
Other End - I don't care what any girl thinks, they are replaceable like car parts.
Balance - This girl is attractive, but there are many out there, if this doesn't't work out, so be it.
2. I don't do favors for girls in order to try to get them to like me
Guys do this crap all the time and it never works. I don't know if it is biology that makes men think that if they do things for women, sex and them liking you is a reward.
In fact the opposite is true. Men think that if they are overly nice, give favors, pay for lunch, buy her things, she will reward that with sexual interest, wrong.
Think about it, if you are doing such things to win her over, how can you not come off as trying too hard? Now I am not saying never do nice things for a girl, but if you do, do them because you want to be nice to a person, never do them expecting it to curry favor for you, it wont.
One End - I will do whatever a girl wants in order to impress her.
Other End - I don't do anything for women ever.
Balance - I don't do things in order to try to please a women for her affections, I only do them when I want to be nice for nothing in return.
3. No Girl is Worth Obsessing about
The more you think about an encounter with a girl or what you're going to do next when you meet them, the more you're going to mess it up. It is simple human nature that your actions and tone of voice when you do meet next will reflect this obsession.
The built in desperate detectors that every girl comes equipped with will fire off quicker than you can blink. Players with balance always are cool when the encounter happens, the men think about it all day and when it comes, they have some act or some plan they put into play which always sets them back.
So the counter-intuitive advice for what to do if you really like a girl and are going to meet her again, don't think about it.
On End - What should I wear tomorrow when I see her, what should I say, I hope I don't look stupid.
Other End - What's Her Name?
Balance - Yes she is attractive, we will see what happens next time we meet.