Many girls go very casual. However, from a guy whose around the club scene both on ships and the one I work at when I'm home, (decent) guys take more interest into a girl who knows how to clean up and dress out for the club, than they do with those girls who show up in booty shorts and a t-shirt. I'm not gonna reccomend anything because..i'm not a girl and I don't know the language lol but i'd say smart casual. As if you were dressing to go to someone's sweet 16 or something like that. Also remember, each night has a theme and you might want to dress the theme. As a guy, i usually dress in jeans and either an oxford or a polo for evenings but on Dusk Blacklight Night, I dress in wild white and neon colors and dye my hair neon green and on Warehouse Underground Club Night, I dress like a "G" (joking).