There are a couple different threads currently circulating about the ideas of socializing, belonging to tribes, making friends, etc. And the OP of this particular thread said to talk in detail. So at the risk of (or better yet, in the interest of) being a pretentious bore, I'll provide some philosophy, tips etc. I've done a lot of socializing in the past and have developed my own deliberate systems. Maybe others can profit.
Philosophy
I'm what you might call a "networker" when it comes to my social life and friendships. I don't rely on any single friend or any single circle of friends to be all things to me. Friends are not "soulmates." Rather, I make multiple friends and circles of friends, and I accept that some will back me up on some things while others will be better company for other things. For example, I can talk politics freely with some friends, while I bite my tongue on that subject with other friends.
One friend might be good for discussing intellectual stuff like philosophy. Another might be good for discussing personal stuff. Other friends are good for going out drinking with. And I have different sets of friends for different activities. And so on.
I call these people "friends," but it might be more accurate to call them "social acquaintances." In meeting these people I simply pick out a social activity that 1) involves an activity (movies nights, happy hour, bowling, cards, etc.); 2) involves some time for socializing and schmoozing (either before, after, or during the activity itself); and 3) repeats itself on a regular basis with roughly the same set of people so that I get to know them well over time.
Sometimes one or two of these "social acquaintances" of mine will turn out to have a lot in common with me, and we might engage in other activities apart from the group where we met. In other words, sometimes a closer friendship might spring up with one or two of these "social acquaintances." But actually, I don't seek out these kinds of closer friendships, and sometimes I actively avoid them. That's because of two reasons:
1) I'm satisfied just doing stuff with the group as a whole. As a "networker," that's what I enjoy and prefer. I prefer floating around and chatting with multiple people in a group rather than doing a one-on-one thing with a single friend or a small group of friends. Example: There was a period when I went to the same happy hour event (pizza and beer) with a large group of people for almost 15 years straight. We occasionally did things with each other outside the activity, but no close friendships popped up. But that was fine. The main thing was that we knew where we would be every Friday evening, and we had lots of good conversation and laughs together.
2) By comparison, a close friendship with one or two friends seems unstable to me. When we were kids it was easy to have close friendships with a few people because we lived on the same block (or in the same dorm) and went to classes together, etc. In other words, even if we had a falling out, simple proximity kept drawing us back together. But now as adults, there isn't much binding us together. It takes a long time to really build strong bonds of friendship, and there are lots of ways to have disagreements and a falling-out in the process. Furthermore, in the event of a falling-out, we not only lose the friendship, but I may feel obliged to quit the group we both originally belonged to as well.
To sum up: I enjoy close friendships when they work out. But my experience is that close friendships require a big investment of time and effort, and in the end there tends to be a lot of turnover in friendships with adults. Even if we don't have a falling-out, lots of real-life things can get in the way and make it difficult to schedule any kind of regular time together.
So I prefer an activity group where I can circulate, and where different people play different roles: Discuss philosophy with one person, personal stuff with another, etc. And if I disagree with one of them and have a falling-out, it's not a big deal. We weren't close friends, after all. We just keep a little distance from each other during the activity until we get past it.
Also, I enjoy engaging in various different activities with different groups of friends during the week. In other words, I can join up with as many groups as my schedule will fit, and have multiple circles of ongoing acquaintances all at the same time. Then, if some drama starts up and I end up quitting one group, it's not a big deal. I still have other activities and friends, and I can just use the freed-up time to join a new group/activity. Investment in each group is minimal, but over time I can get to know a huge number of people around town.
Of course, keeping track of all those people requires some schmoozing skills (small talk skills, etc.). But that's a separate discussion if anyone is interested.
Okay, so how do you do this kind of socializing?
Activities within a big umbrella organization
Many big organizations include some group activities, sometimes lots of group activities. Big churches may have lots of discussion groups, volunteer events, meal events, etc. Senior centers will have gaming groups and leagues (bridge, canasta, cribbage, etc.), exercise and dance groups, lunches a couple times a week, maybe coffee and donuts in the morning. The American Legion and VFW will have happy hour events, dart and billiard leagues, etc. Rod-and-gun clubs will have shooting competitions (skeet, target, combat, archery) and other competition and sporting events. Lodges (Rotaries, Elks, Odd Fellows Lodge, Shriners) will have lots of community service events. Also, all of the above have positions for volunteers to help with running the organization, allowing you to socialize with management as well.
As a networker, a big umbrella organization seems to suit me best. If my activities are all in the same umbrella organization, I can float from one group to the next and still have at least one thing in common with everyone I meet. Also, after a while I get a lot of cross-over in terms of acquaintances and can find pre-existing allies and acquaintances in every new group I join.
And since I'm a networker, I don't mind if I have to invest a little. For example, if I want to check out the Canasta group, I have to learn Canasta. But that's fine: I like cards, and I've always wanted to check out Canasta. So I'm glad I finally have a good reason to sit down and learn. Also, I don't mind volunteering my time and helping set up an activity. I just try to specify some sort of group activity so that I can schmooze as I work.
The point being: I'm a networker. As long as I can schmooze and meet new people and try out new stuff, then it's all good. I'm not making a big investment in order to have a small circle of close friends. I'm into breadth instead of depth. I'm into quantity instead of quality.
By the way, "big umbrella organizations" are great if you're married. You can join and attend some activities as a couple, then the wife and you can each have your own separate activities with different groups. Organizations like churches may even offer child care services, if that's needed.
Other options?
Small independent groups
These would consist of: A bicycling club that you discover on the bulletin board of your local bicycle shop; a group that meets to watch indie films at a local movie house and then go out for pizza to schmooze and discuss what they saw; a book discussion group affiliated with a local bookstore; a philosophy discussion group affiliated with a local bookstore; a group that goes to hear talks at their local museum or library by local speakers and includes a meet-and-greet session for schmoozing afterwards; a therapy group affiliated with a local health center or hospital; parachuting or scuba diving classes and clubs at your local airport or marina. And here's a big one: Meetup.com allows individuals to create their own activity/discussion groups on any topic at the local level. Meetup.com makes it easy to find things like local gaming groups, outing clubs, movie groups, LGBT groups, etc.
I treat these small independent groups separately from the groups that are part of big umbrella social organizations, because the small independent groups usually don't answer to anyone in how they run their operations. As a result, a lot depends on the organizer and how he/she runs things. The groups can be small and cozy and welcoming, or they can be small and claustrophobic and full of drama. (By comparison, activities as part of a big umbrella organization tend to be standardized and monitored by the organization.)
Still, this "smallness" can work to the advantage of a person looking for a small circle of close friends. If you can find that group that is "small and cozy and welcoming," it can be like falling right into a circle of close friends. If you're in a city, Meetup.com can offer literally dozens of different activities with sometimes several groups for each. Just float around try them out until you find a good fit.
Age and sex considerations
Big umbrella organizations can have a heavy female participation. A lot of women just have more free time on their hands (wives). But many women bring their husbands; and many single men socialize at these things as well.
If you're wanting to meet male friends in particular, I think age makes a difference. Younger men tend to show up at bars and happy hour events, and they also like the small independent groups for outing club activities--they are heavy users of Meetup.com. Middle-aged men show up at activities sponsored by big umbrella organizations: Maybe the wife brings them, maybe they are businessmen looking to network in the community, or maybe they're divorced and just wanting a social life. And finally, older folks can be found at the senior center.
Also, the nature of the activity makes a difference. The VFW, rod-and-gun clubs, and sporting activities with Meetup.com are going to be man-heavy. Line dancing at a senior center is going to be woman-heavy.
Small talk
"Small talk" is just a stage in conversation. Two strangers are in proximity, so they zip over 5-10 conversational subjects quickly to see if they have anything in common. It's actually quite efficient and productive when done well. With any luck at all, they can find something in common within a couple minutes. Then they can progress onto the next conversational stage: Talking more in-depth about the subject of mutual interest and developing the beginnings of a bond on that basis.
My rules on small talk:
--Prepare conversation openers and memorize initial questions. Think like an interviewer and have a stock of questions at the ready, plus do any research that might be doable. You can and should get spontaneous with follow-up questions, but initial questions should be prepared and down cold.
--You should try to automate as much of your initial small talk as possible. Only amateurs try to ad-lib small talk. Pros, on the other hand, prepare. Think of a television interviewer. They don't just come up with questions on the spot. They have a research team to find out what's publicly known about an interview subject, then questions are prepared ahead of time.
--Even if it's just small talk with total strangers on the street: Prep a standardized list of small talk openers and questions, and then just go down the list.
--Shy people think that small talk should just come natural, like a machine-gun spitting out bullets. And maybe that's true for extroverts. But small talk can also be studied, practiced, and prepared. In fact introverts can make the best small talkers precisely because they'll study it and dissect it and learn it until they can wield it like a surgeon's knife. (Example: Larry David using small-talk faux pas as regular fodder for his TV show "Curb Your Enthusiasm"; i.e., making millions from analyzing the dynamics of small talk and making fun of it.)
I'll stop there. If anyone wants, I could type up a small-talk "template" along the lines of one I use myself. Just memorize it and use it once or twice a week, and pretty soon it becomes second nature.