Help with this guy! girls and guys help to please! 10 points 4 best answer!?

ok, so i le this guy, and hes a year older than me. he is my little sisters best friends cousin. she tells me that sometimes when im around she will lok at him and he will be looking at me. any tips advice, ways to do my hair,turn ons and turn offs(nothing ual), ways to dress (not to inappropiate), perfume to wear and how to tell if hes flirting? any thing else would b greatly aprecited! thanks!