Fascinating thread, and I have so enjoyed all the responses, not to mention your graciousness in considering each one of these, gryffin.
When I first read the question, I have to admit that I drew a blank. Because most days, the only people who see me are my husband, my daughter, and our cat. So I am not even sure I am trying to convey a message at all. Unless the message is something like Popeye's: I am what I am and that's all that I am.
Dressing has become much more about what feels good (practically speaking) and what feels authentic. And trying to marry these two requirements. Because what feels "authentic" includes more than a touch of luxury and polish -- but also, a huge degree of comfort and ease.
When I do go out and about -- and especially when I'm presenting, speaking, or teaching, I would like people to see me as someone who is integrated, so that her clothes are an expression of herself. This is (obviously) aspirational, because I do not think I appear that way yet. I may appear more modern and more conventionally "stylish" than I used to, but my style remains derivative. I haven't yet learned to speak in my own voice -- or at least, not entirely. I do think I'm getting closer to that. As Gaylene said, it's surprisingly difficult to achieve.
Hmmm. Come to think of it, maybe: I am what I am and that's all that I am is still the message I would like to convey.
And, again -- I think I dress more to achieve a certain set of feelings than to convey a specific message. I want my clothes to make me feel:
Polished
Intelligent
Confident
Fluid (the word really works for me -- conveying a non-sloppy relaxation)
Refined
Thoughtful, considered
Happy (!)
Open
Active