Okay, call me girly if you wish, but believe you me, I grew up with 6 brothers and I was a tomboy until I married my husband more or less. Not that he changed me, I was changing when we re-met, long story..
Okay, I noticed that you only mention black trousers or jeans as a possibility. There are many others! I don't know you or your reasons, but okay, for instance, I don't have the figure I had prior to my baby's birth. It was a c-section and I'm still well big round there... still, there are dresses that are girly but not too girly, one of mine for instance is a white cotton thing, very appealing and flattering, not silly and with a tan a definite winner!
My advice is to experiment with other stuff away from black pants and jeans. If you're the casual type, how about vintage 70s? It's all very playfull and whatever your figure (which I don't know - for all you know you are a model) there is something for everyone and so many styles without going ballrooom. I do all, one at a time and as I say, my figure could be better!