I suggest smiling a lot to him, making kind gestures but more of friendly gestures. Not gonna friend zone ya, but more of making you more likable to 'em. Once you do that, or you're close or already done it, be sure to compliment them on something (like, their looks. eyes, teeth, lips, whatever is their best quality.) Boys usually don't forget when a lady compliments them I heard, and take it to the heart. So, you wanna do something nice to them. As a bonus, your compliment can be something they are insecure about, it'll boost their self esteem?
For behavioral stuff, just act normal, relaxed and confident. Don't act too showy or like you're tryna impress them, because that flunks usually and it's annoying to 'em. That's my best advice, my luck goes to ya.
