All so interesting. My DD is someone who I have often described to people as living art. She is in fact an art student, a painter (visual art) and she also does some conceptual art. I believe she has a unique style of relating to the world that is true to her very thoughtful observations of the world. Her style is consistent with the many activities she participates in and coincides with her strong convictions and ethics. The way she dresses clearly reflects her style and always has. Additionally, you can look at her, and then look at a group of paintings by several artists and you will know which belong to her. If there were a list of causes and you looked at a few pictures of her and saw her move, I think you would be able to pick which were the most meaningful causes to her.
I always considered the type of style my DD has as very innate and not something cultivated, because it has always been present, even before she started painting. She has always been unique and creative. However, I understand the idea of developing and cultivating a unique artistic perspective and style. A successful artist wants their work to be recognized as theirs. They develop a particular style or theme that we know is uniquely theirs. Some mainstream example might be how we would all recognize a Van Gogh, or Monet. So we should also recognize an art students work, a DD Staysfit painting, as unique to her as well, and not belonging to some other painter. What an artist wears, may or may not be consistent with their artistic style or relevant to our recognition of their work as belonging to them. For example, if an artist's signature was to create collages using repurposed clothing, than purchasing new high end designer duds to wear every day might go against their artistic style.
When talking about personality being reflected in ones clothing style, I think it is is really the same as with artists. Some have an innate ability, some cultivate, some are lemmings, and some just don't have it at all.
One last thought. While my DD was home for the holidays, she asked me why I would ever bother looking on Pinterest, reading a fashion blog, or considering what anyone else thought regarding my clothing choices. I am a cultivator, or maybe a lemming? I use these resources for inspiration. It would never occur to my DD to use any of them.
I do think you can cultivate the ability of having style, but it may never be the same as someone who has that skill innately. They have a true gift. They are our icons and inspiration.