There's a few people you probably know (at least a little bit) from work, or meetups, or maybe they live near you.
Ask them to get lunch or grab coffee. Start sending them texts or emails more often.
Some people might say no over and over again or they just might be busy.
Also - if someone asks you to do something - Just say yes. I learned that if you say no the first 1 or 2 times someone asks you to hang out or come to a party - the invitations will stop.
1. We went out and experienced stuff together. Makes us closer and gives us memories to reminisce upon.
2. We've had points of mutual interest and that kind of gave us a push to be together more often and experience more. From music, to programming, to specific food.
3. We made mutual connections. I plan something with friends, I invite them, they invite theirs sometimes, such stuff.
4. We shared stuff about each other. Dreams, goals, relationship talk, stuff like that.
Which distilled the typical requirements to making close friends:
>the three conditions that sociologists since the 1950s have considered crucial to making close friends: proximity; repeated, unplanned interactions; and a setting that encourages people to let their guard down and confide in each other