in terms of clothing and fashion, "sexy" is a misnomer. there is no universal "super attractive" outfit. it's all objective. people wear things that showcase their best attributes and hide their "worst" ones.
are you a leg man? you will like women in short skirts and high heels, because those are the items that accentuate such. same goes with low cut tops...etc.
it's not rocket surgery.
or there's days where you don't feel like being a peacock and you dress functionally.