I would consider myself feminine in that I self-identify as female. It's a subjective thing for me, not one defined by how my peers observe me. Beyond that, I would say that, for me, feminine is strength. Poise. Sharp intellect. I don't associate it with appearance but rather with the way one holds oneself. It doesn't even need to relate to being sexually attractive. For lack of a better word, it's the sheer weight of her own presence a woman feels when she can walk through a room with absolute confidence whether she's in work boots and muddy jeans or dressed to the nines.
I include in that confidence in ones sexuality, actually. This comes in all kinds of forms and different flavours including being confident and assertive amongst more submissive people. Self-knowledge here is key.
Of course many of these traits also relate to the 'masculine' as well. Strength and intelligence are not traditionally feminine traits, those being meekness, chastity and obedience. It is certinally not a parade of 'girly' traits. I think that part of the feminist struggle is actually re-defining things like "masculine" and "feminine", and indeed, to collate a range of other definitions which have no direct association with the dichotomous gender norm. "Charisma" isn't quite broad enough for people who choose not to be male or female.
Edit: Also, in response to an above post OMG! I'M A GIRL! LOOK AT MEEE!