In addition to the well-researched comments below, it's an Art, passed down through the ages.  I brokered natural health products for women before I retired.  Folks from this website contacted me about a breast health/enhancement cream -which I sold to many of them.  I got to 'know' (as much as one can know from phone conversations and consultations) quite a few over the years.  To be a better woman that real women is their goals.  @SB2 you may find this interesting, too.    https://www.sissify.com/