We're all flouting society's most deeply held rules about gender. And we're worried about age appropriateness? Really?
Ageism, sexism, body shaming - a general sense of "let's liberate ourselves ... so we can live under more restrictions than where we started..."
Newsflash - according to a big ol' chunk of the western world, all the clothes being discussed are inappropriate at ANY age for the people in this thread!
So really, find things you feel good about wearing. Feel good about yourself. Also know that your presentation does send a message. If you care about that, then make sure you know what message you mean to send, and that it's the one you mean to send. (If you even care - again, since we're breaking the rules here, not caring seems like a valid answer to me.) There is nothing wrong to my mind about dressing to get attention - provided you are prepared to deal with that attention once you get it. (A lot of times, this is more about attitude than anything else.)
The rules about this stuff gain a whole lot more meaning if you are dealing with a workplace or other organized social setting. Also, a lot of women, both cis and trans, dress to AVOID attention, because sometimes the attention we get is a whole lot of hassle. But we live this way. Y'all are, for the most part, just visiting girl-town, so there's really no problem doing touristy things like mini-skirts. This is yet another example, perhaps, where living there is different than visiting!