I usually pick the large size when it comes to fitted jackets but in this case i decided to go with size medium.  i have a broad back and round shoulders and large upper arms.  when i put the size large on, the body of the jacket looked too boxy on me.  the medium is much more flattering but i cannot put a thick layer on underneath.  when the weather gets cooler, i am pairing this with my herbalist dress and my other sleeveless garments.  i am 135# 36d 38/28/35.