Steps

1. Strike up a conversation. If you haven't met her yet, find something unique about her or the situation the two of you are in and say something about it. If she's a friendly person this should give you enough to talk about until you can start asking her questions to get to know her better.
2. Find something about her that is truly special. Does she have anything about her that is unique? A subtle little quirk or feature that you find endearing, but that no one else seems to notice?
3. 
   Let her know that you think she's special without expecting anything (a phone number, a date) in return. If this girl is really interesting to you, there should be something far from the common that you notice. If she's good looking, she probably gets several compliments a day, so offer her one that is as unique as you believe she may be, like mentioning something about her personality. Here are some examples:
   
   
   • "Hi, I don't mean to make you feel weird or anything, but you've just got the prettiest freckles I've ever seen."
   • "Excuse me, but I can't walk out of here without telling you that you have amazing eyes."
   She'll probably smile, say thank you, look away, and maybe even blush. Remember that even if ultimately, it doesn't work out, you've at least made her day by giving her a true compliment.
4. 
   Offer her your company, and walk away. That is, right before you leave, give her your phone number or screen name, or offer a time and a place to meet, and let her know that if she chooses not to take you up on your offer, you'll never bother her again. Don't give her a chance to accept or reject you. Make your offer and run. Give her a chance to think about it by herself, and wonder "Hmmm...I wonder what he's like." If you do this confidently, she'll feel compelled by her curiosity to get to know you better, and she won't feel like she's being pressured or chased. Also, the fact that she might never see you again will encourage her to follow up on any glimmer of hope she has about you being the guy of her dreams.
5. Don't look back. If she doesn't call or show up, leave her alone. She's not interested, and if that ends up being the case, don't take it personally. However, if she does call you or meet with you, you've probably swept her off her feet! The rest depends on chemistry and compatibility. Good luck!
6. Remember its never about the looks just the impression you made for the first time that will win her over.
7. If she looks down then looks back up, smile at her! It usually means you flattered her!
8. Dont talk about your ex's or problems to her. let her cry her heart out to you no matter how boring it is. sometimes all a girl needs is a shoulder to cry on and sometimes thats all you can be.

Tips

• Here's an example of what you can say (if you're too nervous or busy to strike up a full conversation): "Hey, look, I've gotta go, but you seem like a really amazing person, and I'd like to get to know you better. Here's my number; call me and I'd love to take you out for a cup of coffee and talk. But if you're not interested, that's cool, too. I just didn't want to let this opportunity pass."
• For inspiration, watch the movie 'Office Space' ('Hitch' is awesome, too as is Die Hard) and study the scene where the main character goes up to the waitress (Jennifer Aniston) and lets her know that he'll be at the restaurant next door.
• Approaching a girl while she is with some of her friends (especially girlfriends) will make the approach much more momentous. You have chosen her out of the group and this will make her feel special before you even begin to tell her why you're there.
• The key is to make a woman feel special and appreciated, but there's a fine line between admiration and harassment. If you cross that subtle line and make her feel uncomfortable, you've ruined your chances of sweeping her off her feet.
• If your intentions aren't genuine, and your words aren't honest, then she WILL know. It's the way of the girls mind. But even if you get the girl at first, it's bound to end in disappointment.
• Steps 2 and 3 will probably sweep any woman off her feet, even if you've been married to her for 25 years.
• Try to walk the line between a feel-good compliment and a cheesy pick up line. Be sincere about it, but don't go over the top.
• Remember that all girls are different, and there's no one way to make any girl fall for you. For alternative takes on making a girl get butterflies in her stomach, check out the Related wikiHows below.
• Try to send her really sweet e-mails or messages...girls love them... give yourselves sweet nicknames too
• Be yourself! I know from experience that a girl can tell when you're putting on a persona to appeal to her. If she doesn't like you for who you are, she may not be worth your time..

Warnings

• Be honest. Girls can't stand it when someone (anyone, not just guys) lies to them. One thing girls can't stand is when guys are fake. If a guy says, "I think you have really beautiful hair," and the girl is having a terrible hair day, the guy sounds fake and just plain stupid (unless he really means it). You need to make the girl feel special, but don't just throw compliments around if you don't mean them.
• Don't stare at her if you aren't conversing with her (no matter how beautiful you think she is). Contrary to what some may say, staring is just creepy and rude. Stick to occasional glances, and give a small smile and perhaps a wave if you happen to catch her eye.
• One other thing to remember is that a girl is never impressed if she knows you're trying to impress her. Don't boast. Don't come off looking all proud and superior--that's the surest way to turn her off. Be yourself!
• Some women will NOT be impressed with you if you slip them your number or screen name and run. This can either come off as cowardly or insecure, which is very unappealing to some women. Sometimes you're better off going for it and asking for her number, or maybe suggesting she try going somewhere that you go frequently, like a coffee shop with a nice atmosphere. If she goes, you'll be able to approach her a second time.
• Don't go overboard on the compliments. If you don't know the girl really well and give her more than say two compliments it can come off as creepy or insincere.