How can I start a conversation with the guy I fancy?

Some examples and samples:
Are te in any of my classes @ school?
Do te like cheese?
What's your preferito movie?
Who do te think would be a better President, Obama o Romney?
Do te play football? Baseball? Basketball? Lacrosse?
Hi.
Hey.
What kind of Musica do te like?
What's up?
What're te doing this weekend?
Which came first in your opinion, the chicken o the egg?
Yo.

Make him a sandwich

if u hear him say anything about something u like, for example a tv-show, movie o video-game u could always start talk to him about that.
then it won't seem like you're desperate :) u just want to talk about the awesome thing he brought up to begin with.
don't think it'll work unless u hang out in the same circles though... 'cuz if u don't it might seem wierd to just jump into a conversation, just sayin'.

Say hi and talk to him like te would normally talk to anyone else.

Just ask him about anything

His preferito movie
His preferito reality TV show
His preferito snack
His preferito electronic device
preferito game
preferito subject
If he's in any of ur classes

.....so on