Check these two fashion illustrations by FashionTsunami. They are simple compared to what I like to design myself, but I think I could extrapolate on these.
The girl on the right hand could have some gathering coming to the shoulders and neck with some sheer panelling continuing into the ‘studded bathing suit’ part. Add some boots just above ankle, perhaps draped /wrapped around the foot over sheer.
Repeat the element of sheer panels down the center front.
I must say, I am loving the croquis used, fantastic poses. I have one similar to the left one, but the left is so dramatic, VaVaVoom indeed!