I'm trying to think of a better way to put it
By you, I mean your body's proportions, but also its specific physical aesthetic. For example, a slavic face will modify the way the same outfit would be seen on a germanic or anglo-saxon one. Or maybe you might evoke certain connotations, to take cinematic tropes as an example: dracula, secret agent, etc. You don't have to choose to accentuate it, you could also defy it or engage with it ironically or in other subtle ways.
And beyond the body, your identity. And your personality, humor, mode of speech, etc.
By reception, I mean your audience, the social context. Your peers or the people on the street, etc.
By sources, I mean the context of the garments' production. It could stem from an auteur designer with clear intentions for the piece or a generally understood set of themes - it might also be the historical context of a traditional piece, a breton shirt for example (note that this wouldn't simply include its origins but also where history has taken it over the years)
What's important is that your outfit is itself, in a sense, a work - just as the individual pieces are, even as your body is. You have an audience for the work, the work itself exists in their reception.
You could, for example, put together a fit engaging with detourned symbols of British menswear - from doc martens on the feet to a barbour country coat and a stone island sweater - but the outfit would lose its meaning with an audience that isn't familiar with the citations. Maybe. I'm not that convinced about the importance of an audience to be honest
These are just my personal views fyi and something that I'm still working out
I guess I mean it in the way that an apprentice of any skill begins to learn things by 'hand' or by 'feel', like blacksmith intuitively knowing the melting point of his metals
Or just like how an instrument is sensitive. You know your body, your audience and your citations deeply, by gut.