I usually take the shampoo bottles, after all I pay for them. These dinky little things are great when we go to the pool and shower afterwards or when you go on a quick weekend trip someplace non-hotel.

I did take small towels once or twice, when I swam in the morning, had no plastic bag in the room and needed to pack the wet suit.

I did also "borrow" a UA C blanket. These things are the best to cuddle up to infront of the TV. I have at home also one from KLM, my mom knows how much I like them, but she asked the FA who told her she wouldnt look if my mom packs one. (mom only flies paid WBC)