How to get an older guy to notice me?

I like this guy in the year above me - he's 18 and I'm 16. I know it doesn't sound like a huge difference, but he's alot different to the guys in my year. I sometimes catch him looking at me, and I know he likes bohemian girls which is pretty much my style, but from your point of view, what attracts you to girls a bit younger than you in behaviour and appearance? :)