Ok, here is my advice, and I will tell you that every time this subject comes up, I ost this advice, and it always gets derided.
Don't listen to the derision.
The advice you have been given thus far in the thread will put you directly on the path to being the girl's "Good Friend". That means--in essence--no sex. IF that's what you are looking for, then great, go for it.
But if not, the following advice should serve you well, though it stands in stark contrast to just about everything that has been said in this thread thus far.
Ok, here we go.
Be kind of a jerk. Not a total jerk, just more arrogant than you would normally be. I have no idea why women go for this, but they do. In droves.
I and most of my friends have done "just fine" to "very well" being arrogant jerks.
In highschool I tried to go with the plan my mother had for me: "Be nice, be respectful, think of the girl as a person first". It sounded like gold! I mean who wouldn't like politeness and respect? Right?
I got exactly nowhere. Nothing. Zip. The girls absolutely could not have cared less.
Then my friend Cary, who did very well with women, took me aside while I was complaining one day and told me the truth...
"Treat them bad. Just kind of be arrogant, don't be afraid to belittle them some etc.."
I told him he was crazy.
He said to try it on a girl I liked (Michelle) at a party this weekend. If it didn't work, he'd give me 50 dollars...if it did I owed him 50.
I paid him 50 bucks monday morning. Michelle and I dated for almost year.
The pattern hasn't really changed all that much. I'm not the total jerk that I was in highschool, because I don't need to be anymore.
I now make pretty good money, which picks up a lot of the slack
Your mileage may vary