Looking good in the faces. Nice paintings. Marylin's cleavage seems to have gotten away from you though. Naught but study to remedy that.
I suspicion ye need to dive into the cleavage matter - a total immersion study, you might say. . . Go do a little research into women's breasts. I don't want to just hand you the answer, since it's all about your personal studying and research. But think volume and how the shadow describes the form, rather than putting in stuff you know belongs there any old place or you'll be all willie nearly.
Now that you have your assignment, go forth and get your hands dirty, lad. Field work. . . that's the ticket.
"Not a bit is wasted and the best is yet to come. . ." -- remembered from a dream