I usually load up on the free baby soap and lotion samples at my kids’ pediatrician. I haven’t had to buy soap for my daughter yet and she was born in November. Other than napkins to keep at my desk at work, those are the only free samples I load up on.
I keep a spare key in my wallet but I did repair a car once with a hamburger wrapper and the ketchup packets would have worked.
Sometimes I buy fast food to eat on the run so having ketchup on-hand when I forget to ask for it is useful (no I’m not driving when I use the ketchup).