I never know what clothes to buy or what's supposed to match.
Every time I pick out a shirt, the next second I start questioning the choice. I find it hard to believe that nothing out there matches; stuff that other people wear usually looks good.
I normally go for plain, grayish clothes + jeans because it's the conservative choice, but even then I'm never sure if it looks good.
The workers at the stores are no help at all because they're usually gay ENFjs (not that there's anything wrong with that) and try to get me to buy really avant-garde stuff that's unnecessarily ornate (i.e. pushing the bounds of abstract fashion) or designed to create impact in an openly sexual way, which I'm not really comfortable with.
Plus, I want my own style. I don't want to be given an exact recipe cooked up by someone else. So.. what are the general principles to picking out clothing that matches?