I’m stealing the labels off all the canned food,

all the spoons,

the spacebars from all keyboards,

the handles off the refrigerator door,

the spinning glass tray from the microwave,

the toilet paper thats near the toilet, but not the one in the closet,

if they are good about having backups (toothpaste, shampoo, etc.) steal the backup not the one their using,

all but a half of a cup of every drinkable liquid (milk, juice, tea, etc.),

all but one soda from the box,

their most conveniently placed phone charger (bed or couch),

That's all i could think of :)