Should I play it cool and just be myself and flirt?

Play cool! I don't care what people say. When I used to play cool I actually would get the guys I liked be interested in me. 'til I gave ears to others and started "being myself," then I'd just get walked on a few days after. With time, give yourself the room to flirt, but to start off, just play cool. There's a reason why the word "playing hard to get" exists. It filters up half of the impatient, not really all that TRULY interested, people.

Just flirt, have fun

If being yourself means flirting, then by all means, flirt! If you can't act like yourself around someone, it's not going to work anyway. Give it time before the flirting turns into something physical, but if you don't let him know you're interested, he's not going to stick around :)

I have been there before. You can flirt but always with a limit. A little flirting doesn't hurt. It just makes things more interesting. Just learn how to balance both.

Just be yourself and flirt. When the time is right you'll fell it come naturally and you can take the next step.