Different ways for different people. For one thing, I moved here for graduate school so I had a ready supply of fairly like-minded people of roughly similar int

Different ways for different people. For one thing, I moved here for graduate school so I had a ready supply of fairly like-minded people of roughly similar intelligence and social views to hang out with. Even besides that, as a poor graduate student I was living in a group house when I first got here. Essentially that's a mansion where people rent the bedrooms and share the common spaces (living room, kitchen, etc.) It has its downsides--mostly about keeping things clean and stocking essentials like toilet paper and soap--but it's a great way to meet people both through your roommates and your roommate's friends. And aside from that there are lots of communitarian hobbies you can get involved in. I joined an "urban forestry" group that plants and maintains trees around parks on the weekends. People join board-gaming groups, community gardens, hiking/outdoors groups, meditation centers, reading/book clubs, or similar things. Meetup.com is a good way to find groups that are open to new members. There are also 'community gardens' where you can rent a plot and plant vegetables and it tends to be a good way to meet other gardeners. There are also lots of social sports leagues in cities. The abundance of public parks and sports complexes makes this easy. So you'll usually find flag football leagues, kickball, cricket, etc. For the really indolent there are even leagues for bar-games like bowling or darts or skee-ball. Volunteering is another good option. I briefly volunteered at a high school to do mock-job interviews for kids where I met some folks. I also got involved in a South Asian Young Professionals group, which I then promptly left because it was a status obsessed meat-market, but if that's your thing. . . You can also join classes. Crossfit, for example, develops a culty mentality because the gyms tend to form a community. I joined a martial arts school and made friends with some of the people there. If athletics isn't for you, there are amateur cooking classes, acting, improv, poetry, pottery, painting/art, etc. Density creates viable markets for all sorts of niche services and organizations that can't really survive in a sprawly environment.