hi, in your case specifically, i believe we are selling the sexy look, and not the products (leggings), so be it yoga, or fitness girls, the leggings have to sound sexy in order to be sold, and that's the core marketing story we shall promote as well.
however you are selling it e-commerce way, and in e-commerce, I believe we must focus on soft conversions (engagement, like, share, browse, adding to wish list) more than hard conversions (ie. sales). because it takes appx 7-10 touch points before a customer initiates a conversation with a brand or buys something.
so IMHO, we must start with both FB & Instagram ad campaigns, and chase to grow time spent on products page first, and then cart ads subsequently. beside this other soft conversions we will be tracking by analytics will be like someone checking product description, shipping charges, return policy etc.
beside this, i will STRONGLY advise that we shall avoid giving discounts on website openly, if we want a premium & loyal audience, instead we should offer discounts only to mailing list subscribers and our existing customers.
does it make sense to you? if you find it good, i'll be happy to jump start the work immediately.
pl share your thoughts.
Best, Gaurav