Where do you see these guys?! I could sure use one. Haha, just kidding. But really, take clues from your surroundings. What is he doing? What is he wearing? What is he holding? Then take about 15 million deep breaths and go over and compliment him. "Hey, I really love your shirt/shoes/watch/necklace, where did you get it" "I couldn't help but notice your book and it looks really interesting, do you mind me asking what it's about?" Then introduce yourself and try to ask general questions based on what clues you can pick up on from little things like his clothes and all.
He is no better than your guy friends so try to see him as a friend instead of putting him on a pedestal. Putting someone on a pedestal always makes you see that person as more important(0bviously) and makes it harder to approach anyone at all. See him as being on your level and approach him on a friend level so you can see if you even like him. Then go from there.
Basically, pick up on visual clues and then go with it and be confident.
Good luck!
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