I agree 100% with what Shiny said about you, San. I don't know what that means as far as clothes go. You have mentioned being shy before, and you do seem very quiet and gentle. For me that would translate to a clean, understated style. Now, let me speak generally and not specifically about you: what if you don't LIKE a clean and understated style? I don't think you're necessarily tied to that. My style is pretty colorful and cheerful, but I'm not really very outgoing or cheerful myself. I'm pretty calm and not easily excitable or extroverted, but I wouldn't know what to do with myself if I had to dress that way. I just have a preference from an aesthetic standpoint. I genuinely admire and am impressed by women who can pull off muted or neutral color palettes, but I can't. Lots of times, things that might suit our personalities won't be right on our bodies.
I agree with Tara that body type plays a huge role, at least for me. When I think of style icons that I admire, I think of Twiggy. But if I were to wear the same clothes, besides being unflattering, they just wouldn't have the same effect. I hate to say it, but I think whether we like it or not, or we intend to or not, people will make judgments based on our body types. I share Angie's preference for modesty, but it's really impossible to be modest when you're full-busted. Even when you have the intention, as I do, you're always going to show cleavage, and given the chance, people will always have something to say about it, and assume that you're "showing off" or doing it on purpose (otherwise you would wear a turtleneck, of course)...especially when you're like me and wear a small size but have a big bust. FTR, someone was kind enough to describe my body as "porn star" proportioned. Needless to say we haven't spoken much since.
So while I would like to say modest, I'll never be able to without compromising. We all saw how bad I looked in a high neckline, so I can't say I haven't tried. In any case, I don't think it helped. Even with lots of coverage, it just makes the boobs look even bigger. I can, of course, chalk this up to people's ignorance, but unfortunately their ignorance can wield a lot of influence. To me, a curvy and voluptuous figure is a very classic (and classical) body type, so I often find myself dressing that way, even though it isn't reflective of my personal style at all. I am just drawn to it because I know it will look good on me.
I think trying to convey your personality through your clothes is a personal choice and not a must. If something looks good on me, I'll just wear it. Finding clothes that are flattering and fit well is an annoying enough task without having to add a psychological dimension to it. Sometimes I manage to pull an outfit together that is reflective of my personal style and flattering for my body type...but still wont' accurately represent my personality. It's too tall of an order for me.
As far as classic style, I interpret it as items, colors, patterns, textures, and silhouettes that are timeless, and frequently (though not necessarily) universally flattering. Modern classic is just the most recent iteration of those concepts, at least that's my interpretation. Could be wrong.