Establishing first contact goes hand in hand with visual impression. You may have heard how women are more interested in what the person is on the "inside" rather than what is on the outside. Throw that piece of pretend-knowledge right out the window because, while women may be more forgiving of bad looks than men, the way they form first impressions is exactly the same (it's only later that you have a chance to make up for your looks with your brains).
Research shows that regardless of how politically correct and fair we would like to be, our impression of a person is still strongly based on the first few seconds. People generally think that attractive, well-kempt individuals are smarter, healthier and more sociable. Keep in mind that, these are only the IMPRESSIONS that are left on people as a result of someone's looks. As a side note, these assumptions that we make are only 1/3 correct. In truth, looks only strongly predict someone's sociability. So, now that you know this, you are probably already aware of the first thing you must address: How you look.
However, how you look is only half of what goes into making a good first visual impression. The other important aspect is how you carry yourself. Imagine the hottest stud in a full suit. He looks like he could be a CEO. Now, imagine that same hot CEO hunched over, dragging his feet as he walks, an expression of tension, anxiety or fear on his face. Does he still look hot? Not really. Many people have the potential to be very attractive, but they don't realize that how they carry themselves is not letting them reach it.
Dressing: I can't directly help you here because I don't know what you look like. Speak with various people that you know to find out what they think of your style, and whether there are things you could change in your grooming and clothing to make you more attractive to women.
How you carry yourself: Here's where I can help you. The way you carry yourself has to communicate confidence and strength. Here are some pointers.
-Don't "drag your feet". Walk with a spring in your step. Watch yourself in a mirror. Watch movies or videos of others that you think walk with confidence. Emulate them. -Don't slouch. Slouching communicates a lack of energy, which is a weakness. -Smile. Practice smiling at people as you make eye contact for the first time. It shows confidence and approachability. This is probably one of the most important things to practice. -Try not to stutter or fumble over your own words. If this is a problem for you, then most likely your solution is to consciously slow down your speech. This takes practice, so don't get discouraged. It's normal for people to mumble when they're anxious. Slowing down your speech will help you overcome that. -Watch others who appear confident, strong, and approachable. Try to emulate them.
Now, let me explain how these aspects play into a good first visual impression. Being well groomed and well dressed adds to your physical attractiveness (kind of obvious). Your physical attractiveness is further increased with a confident stance, walk and facial expression. Now here is the key to women: a smile. Yes sir, the ability to smile at any women who makes eye contact with you is a powerful tool. You can think of it as an ice breaker. So, regardless of where you are, you may come across a girl you like. If you have been well dressed and confident, all you have to do is wait for her to look at you, so that you can smile at her.
NOTE: If you're one of those guys who has trouble smiling at women because you get too nervous, then do I have the solution for you! This solution may bother some, but it works, and I've seen it work over and over again. Start going to Gogo bars (it's like a strip club except women are wearing bikinis). There, women will smile at you all the time, which will make it easier for you to smile back. At first you'll be very uncomfortable there, but as you get used to it, you will also get used to smiling at the women first. Trust me, you'll soon find yourself smiling at random women on the streets automatically.
Now, the girl may smile back at you, or look away. If she looked away then she may be uninterested, or too shy. Dealing with shy girls is another story, so for now, if the girl doesn't smile back at you, assume she's not interested and move on to the next one.