Do you use your baggage tags as lint removers?
You don’t need to bring shaving cream. Use the hair conditioner provided in your hotel.
Drinking straws have many uses. Keep your necklaces or chains from getting tangled. Wrap some duct tape around a straw instead of bringing a whole roll.
Dental floss can be used as thread.
Baby shampoo can also be used as laundry detergent, to de-fog your swim or dive goggles, or for a quick wash of clothes in a sink.