This is a fascinating question. I think "styled" is something that everyone does at a generic, base level when we make any choice about what to add to our closets or what items to pull out to wear together. Even someone who swears they don't care about clothes still makes choices about what to have in their closet and wear. And then there's the more technical way of using the word that gets used in fashion discussions. I'm really interested in the more generic end of the spectrum: the choices I make; that more specialized end of the spectrum isn't something I'm drawn to spend much time in.
As an example of the difference, I once saw someone ask on a forum (here or somewhere else, I don't remember where): "I just got these new boots. How should I style them?" I remember thinking, "Style them?? What is she even talking about? Surely you just put them in your closet and then pull them out and wear them."
On my end of the "style them" spectrum, the simple fact that I chose to buy them, and now can choose to wear them when I'm deciding what shoes to wear . . . that's as far as I care to go with styling something. On her end of the spectrum, "style them" meant . . . I'm still not sure what it meant! We're both "styling" what we choose to wear together for a day; she's putting a whole lot more aspiration into it than I am.
Or this example: I am loving the way the Banana Republic offerings look these days. But ...when I take apart their outfits, I find that they're made up of fairly simple clothing items. Yet even if those items were in my closet, I would never end up looking like a Banana Republic photo shoot, because I don't have their stylist following me around belting, tucking, scrunching, combining, popping, and layering—and then posing me against a sepia background.
BUT...the fact that I chose those items and didn't choose something more trendy or edgy from a different store, and that I pulled out that shirt and wore them with those jeans and those boots, DOES mean that I "styled" myself on a basic level.