Be comfortable alone. You don't have to try to act cool or be a try hard; just be loose. Don't set out looking for a girlfriend, or you'll just end up looking desperate. Self confidence and self sufficiency are extremely sexy qualities in a person, and you will not seem like you have either of these if you're begging every girl you meet to go out with you.
Look to make good friends rather than a girlfriend. This means you should talk to as many women as possible, not just girls you're immediately attracted to. Making good friends with women will help you practice holding conversations with them, as well as learning how women feel and think in general. More importantly, you'll be helping yourself feel less lonely without desperately seeking a girlfriend.

Help someone. It could be her, or it could be someone else in the room. Is she carrying something heavy? Say "let me help you with that" and carry it for her. Is someone short on cash? Lend them a few dollars so they can eat lunch. Hold the door open for the next person coming through, even if they haven't reached it yet. In other words, be a kind and generous person. Not only will it get her attention, but it will also make you feel good about yourself. Don't be fake and do nice things only when she's around, though. Chances are, she'll notice that there's a difference between how you treat her, and how you treat others. Help people all the time, in a wide variety of ways. She'll notice, and so will the people she knows, and on the occasion that you come up in a conversation, people will say "They're such a great person!" and this girl will start thinking "Yeah...they are, aren't they?"

Approach tons of girls on a consistent basis. If you see a girl whom you find attractive, go and talk to her (doesn't matter what time it is). And you do that on a regular basis. If you go out one day and sit it out for next few days, it won't work well. Go out regularly and talk to bunch of women. Supermarkets, library, malls, streets, social gatherings any place where you think you might find girls.

Avoid being afraid to fail. Remember, fear of rejection is extremely irrational. If you see a hot girl, go and talk to her. Convey her your intentions right away. Don't digress, no matter what, "Hi, you are cute and I came here to know who you really are." You are looking for a girlfriend, not a friend who is a 'girl'.

Avoid giving yourself time to make excuses. When you see a hot girl, don't make excuses like 'she's probably in a relationship', 'she is on her phone', 'she is jogging', or 'man, I look so bad'. Believe it that there is no valid excuse to not talk to her. At worst she would say 'no' and walk away. You have to try again and again to get good at this.

Keep having fun. This is really important. If you are not having fun while talking to a girl or while looking for her, you are probably taking it too seriously. But if you are having fun, you won't care about the potential rejection and would come out as cool and fun person.

Be yourself to the extreme. If you don't find something she says funny, don't laugh just because she is laughing. Don't try to be something you are not.

Network. The more people you meet, the bigger pool of people you'll have to choose from. Don't be picky about who you meet or how you meet him—the nice old man down the street may have a gorgeous granddaughter your age and the somewhat annoying girl from last night's party might have a friend who's perfect for you.
Go out and pursue hobbies you love. If you're not sure how to start meeting people, sign up for activities that sound fun to you! Check forums, listings, classifieds, and listservs for local events or meetings that are likely to attract people with similar interests or passions. You can also explore new interests or activities. You might find a new hobby and a girlfriend all in one go! Don't depend completely on the internet.

Take care of your physical appearance. No matter how much women would like to admit otherwise, looks are an important part of the dating game. Bad body odor, smelly breath, and greasy, unkempt hair are simply not attractive to most women. Shower regularly, brush your teeth twice a day, and stay in shape. While you don't need to be the best looking person out there, you do need to make a good first impression.
Take pride in your clothing. Again, you don't need to be stylish, but clean, unwrinkled clothes are always better than the opposite. Avoid wearing the same thing every day, especially if it's just sweatpants.
In addition to making you more attractive, taking good care of your physical appearance will boost your self confidence, which in turn, will make you more attractive, boosting your self confidence, and so forth. While cockiness is never a good thing, knowing that you've got good qualities will make you much better at marketing yourself.

Practice genuinely complimenting girls. Challenge yourself to find something beautiful in any girl. It doesn't have to be something physical; it can be a cute gesture, an admirable trait, a talent or skill. Recognizing and expressing true appreciation for any and every girl will make you more attracted to girls and girls more attracted to you.

Be a conversationalist. Don't use “canned material”, “nuclear attraction” routines, or other social robotics. The best way to make a connection with someone is to come from the heart and live fully in the moment. What you say isn't nearly as important as how you say it. Socializing is about exchanging energy, not being a wordsmith.[1] When in doubt, just say “Hi”.
In unconventional strategies, in order to connect with a girl, you have to "dis-connect" with her first. This is actually making the girl take sudden notice of you and making her connect with you instead!

Make her laugh. Girls love people who have a good sense of humor, and the key to having a good sense of humor is to be lighthearted, and unabashedly yourself. As long as you're not making fun of people in a mean-spirited way, anything goes. Is your sense of humor perverted? Slapstick? Sarcastic? Go with anything, as long as you don't try so hard that it becomes fake.
Don't worry about whether or not she thinks you're funny because you know what? If she can't laugh with you, then this isn't a girl you want to spend a lot of time with anyway. And who knows? Maybe another girl—one whom you hadn't noticed before—will be laughing so hard that her soda comes out of her nose, and maybe you've just found your soulmate.

Flirt. Keep all your friendships slightly flirty to avoid falling into the friend zone. This doesn't mean that you want to try to get with all of your girl friends, but being a little flirty will help them remember that you're a potential partner, not just another good friend. Even if they're not interested in you, they may be more likely to set you up with a friend.
Break the touch barrier. Take a few little "touch risks". Be playful without being creepy. Grab their elbow or out your hand on the small of their back to guide them through a crowd, grab their upper arm and laugh if they say something funny, etc. If they don't like it, they'll definitely let you know. Touching someone communicates to them that you find them attractive, and also that you're reasonably confident. Both of these things can make someone feel more attracted to you.

Close the deal. If you like the woman you're talking to, be the one who ends the conversation. This prevents the conversation from lingering into an awkward silence, shows that you're busy (i.e. not needy or desperate), and allows you to end the conversation on a positive note. When you end the conversation, simply say "Hey, I've gotta go, but it's been really good talking to you. Want to continue this over a cup of coffee sometime?" If she says yes, get her phone number and move on. If she says no, just move on. She's not the only girl that will cross your path.

Be assertive. Most women like men to take the initiative, at least at the beginning of the dating period. When you phone her to set a date, have in mind at least two attractive options to offer. Don't contact her and ask her what she wants to do without proposing an alternative yourself, or she will most likely think that you are lazy or not putting enough interest.
For example, if you talk to her and the topic of your date comes up, say something like: "Well, I had thought we could go to this new amazing restaurant downtown... And I have also been wanting to go to the new bowling center in the mall... Did you have anything in mind?" If she likes one of your options, she will tell you, and if she doesn't, she will propose something else and you will have demonstrated your assertiveness. If she says she doesn't care, just choose out of the two.

Be Kind. Just because it gets our attention, doesn't mean teasing us gets our affection. Girl are more sensitive than you'd think, and a simple on-purpose rude remark could cause us to never even think about TALKING to you. Instead compliment heron something good shes done, or be sympathetic if she makes a mistake. But take great caution not to sound sarcastic

Follow Through. If you meet a nice girl who seems interested in you, try to follow through with this. If you like her back, be willing and confident enough to ask her out. Be subtle at first. A person we just met may seem creepy setting up a fancy candle lit dinner for two on our first casual meeting, connection or not. Try taking her out for coffee after school or work. If she says no, then she either isn't ready, or she doesn't like you. Don't persist, this will push her away more, but be friendly until she starts showing a more romantic interest, and then try again.

Go on a date. Once you have met a girl that you feel you truly connect with, you need her to like you. If you've done the above correctly, she's probably already interested, so now you just need to seal the deal. Invite her out for a date or a cup of coffee. Offer to pick her up, walk her there, or take the bus together. Not only is this polite, but it will give the two of you more time to talk during the course of the night.
Don't ask her out over chat or text. Give her a call or ask her in person. Though a small gesture, it means a lot to a girl and shows her that you're not just looking for a quick hookup.
Offer to pay. Go to this date expecting to pay. Again, this shows manners, and it lets the girl know that you're not cheap. She'll probably protest out of politeness, but unless she's really sincere, insist.

Imagine a job interview. There is a big difference between the person who immediately rolls over on his back and begs for a job and the person who knows they have got as much to offer the company as the company has to offer him. When you're with a girl, don't act like you're interviewing to be her partner. Imagine instead that you're interviewing her to be your girlfriend. Putting yourself in the power position will not only make you more attractive to the girl, but it will keep you from choosing the wrong girl just because she'll get with you.

Keep her hooked. After the date, don't text or call right away. Some people set a general rule of waiting for 48 hours before calling a girl back. You don't have to give yourself a set time limit, but you do need to avoid looking desperate. Don't call or text her right after the date—give it at least another night.
Be the one to end the conversation. Whether you're texting or calling, when you feel like the conversation is drawing to a close, make sure you're the one to end it. This will make you seem busier and will always leave her wanting more.
There is nothing wrong with initiating the text/chat/call in the beginning. It's actually showing that you're interested and serious and not looking to play games. Be laid back and relaxed about it. If she sees you're serious about her, she'll take initiative that will surprise her. If she doesn't, she's not that into you.
Wait a few minutes to reply to texts. Replying the instant she texts you will make it look like you're just sitting around waiting to hear from her. Wait 5 to 20 minutes before replying to most texts. Note that you shouldn't wait too long, or the conversation may get lost.

Initiate the second date. If you still feel a good vibe a week or so after the first date, consider asking her out again. Consider making it slightly more romantic than the first—go out to dinner rather than coffee or hang out just the two of you instead of with a group of friends.
Kiss her! If the mood is right and you haven't already, take this opportunity to give her a kiss goodnight. If ever your faces are three inches apart, and you're both staring at each other, it may be a good time to kiss her. Move in slowly to give her time to react, or push you away if she feels uncomfortable. Look for the signs that she wants a kiss. If this is your first kiss with the girl, leave it at that, even if she invites you in. Just reply "Not tonight, but next time!" This will show her you want something more meaningful than just a hookup while conveying that you are still interested.

Repeat. Each relationship evolves differently. Sometimes, you'll have to initiate all of the dates until the two of you are officially a couple. Sometimes, she'll initiate. If the former, do your best to read her signals while you're together, as well as the ones over text to gauge if she's uninterested or if she's just shy.
Gauge signals in person. If she responds well to your flirting, laughs at your jokes, and seems comfortable around you, she's probably interested. On the other hand, if she sits away from you with her arms crossed or if she refuses to look you in the eye, she's probably not. Try grabbing her hand when you're walking or putting your hand just above her knee during a movie or during dinner. If she pulls away or seems uncomfortable, she probably hasn't warmed up to you just yet.
Gauge signals over text. If you feel like you're always stretching to keep a text conversation going or she always replies with short answers such as "great." "okay." "yeah." etc., you can assume that she's probably not interested. She likely knows these answers don't lend their way to a meaningful conversation, and is just trying to be polite by responding without giving you the wrong idea. However, in person signals are always easier to rely on. If you're getting mixed signals, go with the in-person ones over the signals you get over text. In a dire situation, talk to mutual friends to help you better understand her behavior.

Ask her to be your girlfriend. Once you are pretty sure that there's strong mutual attraction, ask her to be your girlfriend. You can do this in a big, creative way or simply ask her in person. Be sure to never ask this over text or chat (even just over the phone is questionable). Don't change your Facebook relationship status or refer to her as your girlfriend until she responds!

Be patient. Life doesn't normally work on the schedule you envision. Your future girlfriend might cross your path tomorrow or two years from now. A healthy relationship will color your world no matter how old you are, so don't rush into things, or else you might end up forcing the wrong person into the girlfriend role, which will cause pain for everyone involved.