Excellent and thoughtful question, Suz, and a couple are a challenge for me: Just Enough Structure and Irregular Outfit Juxtaposition, although I think the latter sounds like so much fun, but I, too, get concerned about a "costume-y" appearance or one that is too "forced." As for structure, I just haven't played around with it yet, enough, to know what I'm really doing, so there's a little trepidation with this one.
I'm more in comfort zone with Combining the Classics with Trends and High-Low Style and I really enjoy the Classics with Trends options best.
Thanks for bringing up this topic, because by exploring it, I think we'll be more willing to try these approaches in our own way.