Once I stopped carrying around my bloody axe, people found me much more approachable.
* ba da BOOM chi *
Some guys are like the hare, good at initial first contact, others are like the tortoise, good in the long run. So the comments about patience and persistence should be weighted just the same in your mind as the advice about the fleeting first contact moments. If it's really meant to be something serious, then the first contact shouldn't be the single test that counts as your entire grade.
I'm a little polarizing on first contact. People either find me incredibly charming and slightly odd, or they find me a bit frightening and way too odd. I'm the same -- it's just who they are that determines their reaction. So there's only so much you can do on first contact. It's really less about you, and almost all about who they are and how they are feeling at that moment. Accordingly, from your perspective, you should consider the outcome of "first contact" as a random variable. To be more explicit, you can fret all you want about that moment, but in the end, you have no control, so just relax and be yourself, however you feel at that moment. The outcome is out of your hands.
Now, the REST of the process, that's where you have control. And my advice is patience and persistence. My significant other in my previous relationship stuck with me for 6 months, just being so nice and charming and kind, I finally woke up one day, with the help of an observant friend, and said "hey, this one is worth giving it a go with."
In my current relationship, we met on here two years ago. Neither of us thought anything serious would have been possible, but spent that two years becoming really close friends, and then one day, lightning and thunder hit us both simultaneously and we fell into the deep end of the pool.
So, uh... yeah.
* files nails *