This is a great thread, love it!
My favorite part - my ass.
One part genetics, one part a few thousand miles jogged over the years (no exaggeration, I used to be an obsessive runner). My ass is shapely and very feminine, and rolls nice into the elegant swoop of my back .
Runner up - my hips. Purely genetics, I've been blessed with an hour glass figure, my hips are the ticket, in conjunction with my ass.
What it means to me- I believe the two go a very long way to helping me pass. I've been asked on a few occasions where I got my curves, by ciswoman that were aware of me (and were a lil' envious

). It means a great deal to me to see a classic woman's shape in the mirror .
Is it old or new or both - actually, old. I grew breasts and became hippie during puberty, but once I coupled HRT with physical fitness my shape just exploded.