Another interesting dynamic in Seattle is that people seem to assume all the people they know already know each other, which means nobody tries to introduce people. I have an old friend up there who used to insist I already knew people I hadn't met, which was frustrating. The result of this tendency is a social network with a highly connected center and a lot of poorly connected leaves. This structure really revealed itself when my social network was struck by a tragedy where several people were victims of a shooting -- there was a group of people who all had direct connections to at least one victim, and another group who didn't know any of the victims personally but a majority of their friends had. I was in the latter group and I found it very strange.
It was a huge contrast when I moved to the Bay Area, where people assumed everyone was a transplant and went out of their way to do introductions. I was at a party once where I was reintroduced to the same person four times -- someone who I had already met years earlier.
[0]:http://johnassaraf.com/goal-achieving-2/a-tale-of-two-shoe-s...
Gladwell observed in Tipping Point that most peoples' social circle is usually created by one high connection "maven" who connects many low connection end nodes. You want to try to move closer to how that maven operates.
Concretely: If you go out with a friend, and end up becoming buddies with the waitress, and then also know of an after party you can bring the friend to, by virtue of your network, you will constantly be getting solicited to hang out. Even more quantitatively: if you can average +2 casual connections per day when you try, you'll be doing very well. But two connections in a day is very difficult for most people on HN; you'll have to work and experiment on how to achieve that.