My skin is very prone to allergic reactions when I try new products, so I always pack my own body wash, shampoo, etc. (100 ml or less since I generally travel with carry-on only). Sunscreen is a particular challenge since I can only use physical sunscreens (zinc or titanium) which can be hard to locate in most places. If I'm short on space, hubby can use the stuff the hotel provides since he isn't likely to break out in a vacation-ruining rash.