Wears makeup and is very feminine. Femme's are harder to distinguish from straight women, butches are not. Best I can do for now. Butch and Femme are mostly a state of mind. I have known many a femme with a butch heart and a few butches whose heart would make you weep.
Outside appearances mean nothing.
Unless you are the religious right. Then you are an easy target. Does wearing a dress make you femme and wearing a pair of Levi's and a t-shirt make you butch. Butch and femme words cause lots of discussion needlessly. I am both and I am neither.