I’m sure if we could all afford gold-embroidered gowns and it was culturally appropriate for women to dress like royalty, we all would.
I’ve worn skinny jeans for as long as I remember. I’ve recently come to the conclusion not to buy anymore, but that’s because they’re simply uncomfortable for me, not because of immodesty.
Jeans that show a woman’s figure/legs are not inherently sinful. I think it’s worth noting that in other cultures, women can go topless on beaches and it’s not taken as a sexual thing. The problem is moreso our culture’s obsession with sex and the taboo that was created which automatically equates the body to something sexual.
If a woman’s intent in wearing skinny jeans is to show off her body, that’s immodest and may be sinful. But if that’s not her intent, any lust that results is often the fault of the one who lusts.
EDIT TO ADD: Of course, if one wants to dress carefully to avoid causing undesired thoughts even though those thoughts wouldn’t necessarily be her fault or responsibility, that is commendable. Dress according to a well-informed conscience.