find something he's doing that will get you to ask him something interesting.
heres an example that actually one of my ex's used
i was looking at some event that I was sorta kinda interested in, and she saw me, came up to me and said "watcha watching" I turned to her and said, just something that sorta caught my eye. we eventually got to talking and voilah. the ex thing don't worry about that's my problem my point here is to get you started. my dad once said "be caught, doing great things, people notice"
Smile at him from afar but if he looks, look away quickly and then look back to check if he is looking. If he is then look away and look embarrassed. This is actually something I do naturally and only recently have I figured out that it works and gets guys to approach.
Ahh I'm such a stalkerish weirdo!
BE that stalkerish weirdo! actually no.. bad idea lol.