Outfits.

Seriously, everyone in the show wears the exact same thing EVERY DAY. Please don't try making new outfits, it makes the characters seem very OOC. Marinette won't probably be wearing a crop-top with booty shorts, and Adrien would probably be personally executed by his father if he ever dared to dress like a slob.

The only exceptions are in AUs and school-dances, for obvious reasons.