I've never shopped on these sites. What are people typically buying? Is there something I should be stocking up on?
The next time you need a kitchen gadget, tool, measuring cup, belt, socks, pencil. Anything. Buy it on aliexpress and save a ton, in exchange for very long shipping times, and you pretty much can't return anything (you can get refunds for defective stuff, but not for wrong size/color etc).
And it's not just a Chinese clone of the item, it's the exact same item, with a different name printed on it.
Head over to banggood.com and see what you've been missing.