With the basics down, you should be refining your buying habits—at least if you're shopping with the intent to resell. While there are always going to be wacky pieces that people will go crazy for because they're something only Supreme could do (aka, Supreme Fire Extinguisher) buying anything with minimal designs and clear Supreme branding are always going to have a place on the market.

If you buy only the obscure or insanely patterned stuff, or (on the opposite end of the spectrum) something with not enough branding, you'll be caught with merch you can't sell. If you're doubtful, there's a reason why the black box logo hats vanish in the first couple minutes, and why you can always buy a Supreme oxford shirt or Supreme x Hanes undershirt pack.