I like the smart, classy look on girls. It's far from slutty and extremely attractive (well in my eyes anyway). Heels, nice jeans (doesn't have to be a typical dark blue or black pair, could be burgundy or cream even) or skirt or normal trousers, a nice top and, the best part of the outfit, a casual blazer.
I like the idea of a girl who's dressed to do something active. Shorts, a loose fitting, comfortable t-shirt, sneakers. You know, the way you end up looking when you're going to be doing something that requires being out in the sun all day building up a sweat so you don't concern yourself too much with your looks. That to me is the ideal look.
jeans and a solid colored tank top. not with spagetti straps but with ones that cover your bra straps if you're trying to avoid looking slutty:)
Something that shows your shape but not a lot of skin. Like tight jeans and a fitted shirt that only shows slight to no cleavage. Or a short (but not super mini) skirt with pantyhose or tights and a high cut shirt.