Essential when staying in a hostel
A washable sleeping bag liner An extra-long charging cable in case your bed is located far from an electrical outlet Earplugs and sleep mask Quick-drying, a sarong or Turkish towel can also be used as a privacy screen if you're on a bottom bunk or to cover up while visiting churches in Rome........... Shower sandals or flip flops A universal travel charger (various) if you are visiting different countries (continents) with different plugs At least one lock for the lockers, better a TSA-friendly one to use on your luggage as well. The truth is, it is very common for solo travelers to get together while on the road. At the very least you can find someone to have a drink with, at best you meet a friend for life! The best way to start making connections when staying in a hostel is to have a little chat with your roommates. If you are traveling alone, try to choose the 3-6 bed mixed dorms. This is small enough that it feels like a community, but not so small that there is any discomfort