[Cyasarin]

Like some people already stated, knowing Japanese might help...So yeah, that covers the 1st part of my ways.
But usually what I do is naturally strike up a conversation with someone. I'll be waiting in the line at the fair and it'll be slow-moving or cold or something and all I have to do is make a comment and someone will turn around and comment me back. This one chick is just chilling in line to get on this ride and she goes "Hey, I love your hoodie." And we talked until the line moved up and seperated us.
Compliments seem to work nicely like that. But if you want friends, don't just compliment someone...maybe ask them where/how they got whatever or tell them why you like whatever it is you complimented them for.
What you might could do is [might be a little bad, but that's how me and my 2nd best friend met] listen in on a conversation between a small group of people and if it's interesting, comment them or ask them a question. I was talking to my best best friend about my fanfictions when my 2nd comes up behind me [no idea who she is right then] and asks, "Do you like anime?" And now we're like super close.
And it might be a little smart to impress people, too. If you want friends, dress up and present yourself in a nice way. My friends and I have no problem with average people, but when some really hot chick or awesome looking guy walks by with a nice presentation [nice clean clothes, nice smile and character, etc.], we're like, "I bet they would be a cool person to chill with."