Twitter suit guy may be annoying but his series on developing your own style from the ground up is great:

Everything is contextual to an aesthetic. A hundred years ago, the scope for good taste—what Bourdieu would describe as legitimate taste—was confined to the taste of the ruling class. That is no longer the case today. This means rules about colors, silhouettes, proportions, and other such ideas are contextual to the aesthetic you’re trying to create. I’ve written some posts about how to think about silhouettes and color. But whenever a reader emails me to ask whether black pairs with blue or if a particular garment fits correctly, I feel that, in today’s culturally open world, you have to start with the aesthetic, not compartmentalize things as universal rules. This is partly why some guys who favor classic tailored clothing struggle with casualwear—they try to transport cultural ideas about suits and sport coats to very different aesthetics, such as workwear or sportswear. Sometimes rules can stretch across aesthetic spaces (like ideas linking romantic languages); sometimes, they do not (like trying to apply English grammar rules to Chinese). Derive your rules from aesthetics and your aesthetics from culture.