1. I'm an introvert.
2. I'm a bit of a perfectionist.
I don't dislike all attention -- just because I'm an introvert doesn't mean I don't like talking to people. But I much prefer attention and interaction on my own terms, in smallish doses, at times and places of my choosing. I want to turn attention on when I want it and have the default state be pretty much off.
Therefore, I want any attracting of attention I do to be a result strictly of my behavior rather than my appearance. I'll attract attention by my actions if and only if I want to, since my actions are under my control and can be turned on or off at any time, directed at specific people, etc. Clothing and grooming choices, on the other hand, send a message to everyone who can see them, and that message cannot be altered or stopped without resources and effort. There isn't much I want to say to the whole world. Some version of "I am competent, I am respectable, I am professional, I belong here, and if you fuck with me you will regret it (but I am not a threat so long as you don't start anything)," is usually good. Competent and professional mean "Pay attention to me when I ask you to," and the rest more or less adds up to "and leave me alone the rest of the time."
There are three kinds of attention: general situational awareness, interaction, and directed observation.
General awareness is when people notice that I've entered a room and say "hi" if they know me, step around me on the sidewalk, or notice that I look particularly cheerful today. "There's Theresa, she looks really involved in that book," or "There's some odd office-worker type curled up on that train seat scribbling in a little notebook," are general awareness kinds of noticing me. I'm fine with this. My presence, general demeanor, and current activity are perfectly good things for people to notice. They're picking up on those clothing and body language signals and reacting appropriately.
People-watching, when appropriately divided among the people present, is also fine. If someone is watching all the people and I am just part of the crowd, that is fine. If I am being singled out, watched more closely or by more people than others present, that is problematic.
Interaction is when information is being deliberately transmitted. Both (all) parties are aware of the interaction, whether they are participating equally or someone is performing and someone is watching. I expect and prefer people to pay attention to me when I am doing something interesting so that they can watch or participate. This includes situations in which I'm telling a story, demonstrating how to do something, or otherwise performing. I'm doing something specifically so that other people can watch; they've been invited, so it's okay. If I am doing something that is not intended for other people to watch, then I don't want them watching, except in the general situational awareness sense.
This is why there is a difference between dances with steps and dances without steps. Dances with steps are a performance, intended for other people to observe. Dances without steps are about my relationship with the music. They are not for other people. Other people can be present, doing their own thing or watching the crowd in general, but directed observation is a problem. (This is one of those spots where I'm weird, I know.)
I don't get much unwanted interaction; those few unsolicited interactions I have with strangers tend to be short, polite, and positive ("Do you know where [address] is?" "I like your sweater."). I presume this means my clothing and behavioral signals are operating correctly. As an introvert, I run out of ability to deal with more complicated interactions sometimes, but that's not really a problem with the attention part.
Directed observation is the kind of attention I don't want. This is when people are watching me, specifically, and I have not invited them to do so. I may or may not be aware of the observation. There can be a fairly thin line between directed observation and general situational awareness. As a rule, someone engaging in situational awareness is doing something else too, even if that's just daydreaming. If they stop what they're doing to watch more closely, it starts turning into directed observation.
Persons who are observing me are doing one of three things: forming an opinion about me, considering me as a decorative object, or considering starting an interaction.
I generally prefer that people's opinions of me be based mostly on my deliberate actions, or at least on things I know about. That is, I'd much rather a hiring decision be based on the job interview than on the hidden camera watching me fidget in the lobby beforehand. I have weird body language, and my neutral or resting postures sometimes look hostile, uncomfortable, or upset. I'd prefer people not come to negative conclusions about me without actually interacting.
Opinion-forming is why I don't like people watching when I'm doing non-performance things like dancing or playing the piano or writing. The things I do as performances are things I'm good at; particularly, things I'm good at doing in a way that I would like other people to watch. The things I don't do as performances are things I'm not good at, or things I don't think are interesting to watch, or things that aren't finished yet. (So I wouldn't want people watching while I was practicing a song or writing a story, but once the thing was finished I could show it off.)
There's no way to stop people from forming opinions based on observation instead of interaction -- besides, that wouldn't be healthy for them, since there's a different set of information available when interaction isn't affecting my behavior. But I don't want observation to be the main thing an opinion's based on; general awareness should be enough to get a vague idea of whether the person would like to get to know me, and then interaction can form the main body of opinion.
Persons regarding me as a decorative object have made incorrect assumptions and will soon be disappointed. I am not decorative; I fidget, and scratch, and make weird faces. In a perfect world, being disappointed at my not being decorative would be the observers' problem, not mine. In practice, they tend to form negative opinions of various sorts, or even start unpleasant interactions, so I prefer that they not form those expectations in the first place.
This is where this hooks back in to the butch/femme thing. Femme clothes carry messages like "Look at me!" "I'm sexy!" and "This would be nice to touch!". Those are not messages I want to be broadcasting. If I want to send them, I'll be sending them at very specific times to very specific people. They are not good messages for my clothing, since clothing sends messages to everyone indiscriminately. Most women lean more towards fulfilling decorative expectations than preventing them, so they may wear clothes (or makeup or accessories or what have you) that are intended to draw attention, then manage their posture and body language so that observers aren't startled, disgusted, or otherwise disappointed in their expectations. That's more effort than I want to go to, so I don't wear, say, skirts in which I would have to sit with my knees together to keep my underwear to myself. I don't like the distraction of thinking about where my knees are, and I really don't want to put in the time and effort to make keeping them together an automatic habit. (I suspect part of the reason most women lean more towards decorative than I do is that they learned acceptably decorative postures young, so they don't have to think about them nearly as much regardless of what they're wearing.)
People might also be observing me because they are considering starting an interaction. This is frequently innocuous. They could be waiting for me to finish another conversation before speaking, or reach a good stopping point in my activity before interrupting, or trying to tell whether I'm actually as cranky as I look before putting themselves in the line of fire. However, they could also be hesitating because the interaction they are considering is inappropriate or unwanted (or they suspect it may be inappropriate or unwanted).
If I notice someone watching me, I will generally attempt to spark the interaction. If they were waiting for an invitation or considering something reasonable, they'll generally get on with it. If they were just staring off into space, they'll startle a bit, apologize, and direct their eyeballs somewhere else. And if they were considering something inappropriate, I get to find out about it and shut them down (in theory; I can't remember the last time this actually happened). This generally also puts off the decorative-object people; anyone who continues staring is being creepy and can be deliberately offended.
If I'm too introverty to want to interact, I'll keep myself out of situations where other people are likely to start interactions. So if you're in a position where you're wondering whether you should start an interaction with me, yes, you should. If you sit there thinking about it I will notice you thinking and be increasingly uncomfortable until you decide against it and go do something else instead.
So there you are: interaction good, until it's too much; general situational awareness acceptable as long as there's no particular focus on me; directed observation bad.