There is no "way" to flirt with someone.
The main thing to do is just to talk to the person and laugh a lot. If you are a girl play with your hair a little and smile a lot. If your a guy usually...
We usually try to crack a joke whether it be funny or not even close to being funny. Either way, a girl will laugh no matter what, at least one that thinks of you. IF they don't, don't even bother to...
I think the best way is to try to be yourself. Maybe blush a little while talking to him, push your bangs (if you have any) out of your eyes once in a while. Talk about things he's interested in,...