armstrong said:
I'm doing this and am currently in the same boat as the OP. It becomes a challenge to meet women when all of your friends are either married or in a relationship and don't go out anymore.
I think joining clubs or groups is a good idea, but what I'd really like to hear is what some of you would do if YOU were in this situation. Let's say you just moved to a new city all by yourself. You don't know anybody. What would you do?
I have certain hobbies, music for example. So I would look up the local scenes and maybe hit those up. Or if public transit was adequate I would just take a day and go all over the place. Maybe end up at a bar and have a drink or two. Have quick bites to eat and keep it moving. If I see some people that seem cool I would strike up conversations. If you kill the desperation when it comes to girls, you can actually have decent conversations with them and build some rapport. That can turn into party invitations or other social gatherings.
I would also join a local gym. Making gym buddies is an EXCELLENT way to meet new people.
Most people want you to bring something to the table. So if you're not cool, good looking, well mannered, easy going, or fun, you're going to have a harder time. Look for opportunities to meet new people everywhere. And not just women.
That's how you build a social life.
Also, you can check for events in your area. The internet is full of things for major cities. LA has the LA Weekly, and I'm sure NYC has something similar.
The key is to go out and explore with an open mind. Be cool, have fun, and don't be so desperate. That desperation stems from somewhere, and you might need to look within yourself to figure it out. People can sense a needy vibe and that pushes people away.
P.S. OP, it's OK not to have a girl at the moment.