I was trying to explain to someone the other night the whole idea of Being A Girl™. You can identify as a woman, or be biologically female, but these two things are separate from Being A Girl™. Girling™ is a technical performance skill. A lot of people -- including ciswomen, most of whom are raised in the culture from birth -- never learn it. Some people choose to spend their time and energy elsewhere, and this is cool. Some people never get a chance to learn it, and I think this is sad, because everyone should have the opportunity to learn anything they're interested in.
Girling™ is theatrical costuming for everyday life. There's equipment, there's technique, there's history. There's practice. Lots and lots and lots of practice. You have to learn how to use all the weird pieces of clothing and shoes and pots of paint to create different styles, different moods -- and then, if you're going to Girl™ that day, you have to get up in the morning and figure out which one you want, and how to sort through your stock of Girling™ materials to attain it.
As in most performing arts, there is a community that is heavily invested in Girling™, and in that community there is a lot of pressure to always Girl™ bigger, and better, and more expensively. The most extreme can get to Girling™ to the extent where they ignore practical considerations, from small things like choosing to accept blisters as the price of wearing the shoes they want, up to and including sacrificing things like their health and happiness. There are also a lot of people who Girl™ as amateurs, for fun, when they have the time and resources. Unlike other performing arts, Girling™ is often preached to the amateurs and non-participants as a requirement, not a piece of entertainment for yourself and others. There's nothing wrong with Girling™; there's a lot wrong with shaming yourself or others for not Girling™ "well enough".
Men who have taken up Being A Girl™ are still unusual. The behavior is traditionally accepted -- if you can always call it that -- only from drag queens, who are presumed to be the same things as transvestites and also presumed to be sexually interested in other men. More broadly, Girling™ from someone who identifies as male is often assumed to be isomorphic with homosexuality, which is also not particularly accurate. A lot of men who are both openly gay or bi and also into Girling™ are more willing to do it publicly than straight or closeted men, but this is also not the case 100% of the time. Eddie Izzard is a straight male-identified transvestite; he doesn't always bother, but he Girls™ freely and fiercely when he does kit up in female-styled clothes. His DVD Dressed To Kill isn't kidding.
The point of Girling™ isn't always to look female. I call it that mainly because verbing "(to be a) girl" is something people in my culture will be able to at least mostly understand -- we have the adjective "girly" that covers a lot of the same ground, although it also (not always complimentarily) also covers more. Usually the point is to look decorated and in many styles that also emphasizes pretty, but men who Girl™ don't pad out like drag queens and female impersonators, and generally they come out looking like pretty men. Bill Kaulitz of the band Tokio Hotel (straight, so far as I am aware) and Adam Lambert (openly gay) both go for a very decorated glam look with Goth and industrial influences, which is a style that encourages theatrical paint and clothing that hug body lines closely -- drainpipe trousers and fitted shirts for clothing, and high-contrast makeup to emphasize eyes, eyebrows, and cheekbones. They're both clearly male, and also very clearly Girling™ with great skill and enthusiasm.
Men who Girl™ a lot tend to attract a large female fan following. Women who like Being A Girl™ -- especially very young women, to whom choosing what impression they want to give other people is often a paramount concern -- see a kindred spirit. It's a visible indicator that someone they're a fan of has something in common with them, but also a level of skill they admire, and might aspire to. Glamour and confidence is part of the cultural baggage attached to Being A Girl™; it's often taught, explicitly or implicitly, that Girling™ really well will automatically bring you the status that comes from other people believing you are happy with yourself. (It goes the other way, mostly, but never mind. There's also an ugly element of wanting other people to envy you that goes with displaying great aptitude for anything people value as a skill that I'm not going to get into. You deal with other humans, you probably already have a good idea of how that goes.) Part of their appeal comes from the perception that they're Girling™ hard enough to get away with it, despite perceived social objection. The same thing draws female fans to female celebrities like Carmen Electra or Angelina Jolie or (sigh) Miley Cyrus/Hannah Montana: They imagine that Girling™ at a Hollywood level would make them feel as fantastic as (insert celebrity here) appears to be.
What prompted this conversation was my dinner companion asking why in the name of little green apples Johnny Weir has such a devoted female following, even though he is extremely married and, if it is at all physically possible, slightly gayer than the day is long. Weir has a particularly admiring cloud of fangirls around him for a lot of reasons -- he's young, he's attractive, he's bright, he's artistic, he flirts for fun, he has a lot of female friends, the off switch on his mouth sometimes has an unfortunate amount of lag -- but the one most applicable here is that not only is he extremely good at Girling™, but he demonstrates an uncommon amount of respect for the women who do it, too. He may not be attracted to women, but he clearly thinks they're beautiful. They don't seem to be for sale anymore, but he did a collection of the proverbial "little black dresses" for eDressMe a couple of years ago, and some of the pictures are still floating around. He's working in very small sample sizes (0-2) because that's what the agency sends you when you call up asking for runway models and fail to specify otherwise, but those are all unusually curvaceous for couture dresses: The models in the cocktail-length frocks are padded out on top/standing very strategically, and the lines of the pink gown with the shoulder puff are standing away from the hip and décolletage of the mannequin he's using because they haven't given him one hourglassy enough. I could wear one of those, and I would if I had the money to scare one up in my size. There's a lot to be said for someone whose style of Girling™ you admire making noises like they think it might work on someone kind of like you.