Before we get started, let's get one thing clear: This is not about hating Miley Cyrus. In fact, as someone who appreciates the Miley Cyrus attitude, I hesitate to tell anyone what to do with their Halloween costume or their life; the point is that we are all supposed to figure out what is right for us. But still, for the good of the cause, please do not be Miley Cyrus for Halloween. Even ironically.
There are a number of reasons not to wear hot pants and a teddy bear backpack around on October 31, the first of them being practicality: It will be cold, and it's a drag lugging all those props around. At this point in the media cycle, there will probably be four or five Mileys at any given parade. Overexposure is a real concern. And then there's the sexy costume issue, which is depressing — not because of self-expression (that's great), but because the sexy Halloween costume has come to represent our discomfort with female sexuality on the 364 other days of the year. Yes, Miley's hyper, tongue-wagging "post-erotic" version of sexiness is partially a response to this prudishness, but a parody of parody is tricky business, and as Miley herself can tell you, intention doesn't always translate. To a majority of the drunk people in the room, a self-aware Miley Cyrus costume will still scan as "that girl who humped a foam finger."
Put simply, it is difficult to be clever or provocative in a situation where most people refuse to acknowledge complexity of any kind. If you are Miley Cyrus, and you are crafting a "strategic hot mess" in order to reclaim your identity, start a national conversation, and/or sell a shitload of records, that effort has a payoff. If you are just a human going to a Halloween party, it's not worth it. Just get a giant curly wig and be Lorde.