if you have enough problems socially that you would make a post like this on a messageboard, youre not going to be able to learn any technique that will suddenly enable you to walk up to a stranger and make friends with them. in a big city, no one even does that. walk up to a stranger and start talking, they will generally want nothing to do with you unless they are tourists.

the easiest way for people who have no friends to start making some, is to join a club of some sort. it is much easier to talk to strangers when you know they have a similar interest.

if youre hanging out at bars or parties and you feel like the outcast, its not likely that will change by continuing to go. you cant force yourself to have fun.