How to make a complete stranger notice you?

Well i've met him once, through my best friends ex boyfriend... so he is my best friends ex boyfriends friend haha i know.


But he keeps staring at me, smirking at me etc


and i want to know how can i get to know him, i don't want to just jump on him and introduce myself i want to make it subtle. But how do i get him to notice me? how can i stand out from the rest or w.e, i think he is a year older then me though, im 17 and he is either 18/19 not sure.How to make a complete stranger notice you?
Wave and say how are you.How to make a complete stranger notice you?
You can try showing cleavage but doing the subtle thing wont always do the trick. In the same way girls would want a guy to just come up to them, guys want that too.
When you are around him and he is looking at you, smile, wave, say hi, give him a flirty look. Give him subtle flirty body language that hints to him that you like him.