Religion has the benefit of being a massive (1B+ for the major ones), well established institution for bringing people together, the recurring nature of meet-up

Religion has the benefit of being a massive (1B+ for the major ones), well established institution for bringing people together, the recurring nature of meet-ups for church and / or prayer help to establish routine. What I've found is that for those who are not religious, the hardest part about building a social structure from scratch is establishing some routine. I moved from Boston to Portland a few years ago and didn't know anyone. I tried everything from Meetups (solid if you're looking for friends of the opposite sex and people your age -- especially if you're a millennial / gen X), volunteering (great for meeting a wide variety of people but can be difficult to come across the same people over and over unless you share a common bond, like work) and sports (best for last minute get together, but sometimes to schedule can be too rigid if you don't dedicate yourself). They all have their benefits, and you'll never enjoy every type of person you meet in a certain community. The key above all is getting together with people you like on a semi-regular basis. Even twice a month on a long enough timescale is enough to establish a strong tie.