Hostel Gear
A combination lock is necessary for your locker to keep valuables safe and for important things that won't fit in a locker, like a suitcase you're leaving behind in the room, you can invest in a wire mesh luggage protector. (It's also a great tool for long train rides in 3rd world countries where you want to sleep without worrying about bag snatchers.)
Most European Hostels charge for sheet and towel rentals separately, (and don't allow sleeping bags in lieu of sheets.) So be prepared to pay a one-time $10-15 in addition to your booking. (You can bring your own but it's hardly worth the space it would take up.)
If I'm only staying a night or two I skip the towel rental and just use dry shampoo :)
But I do bring a small washcloth to dry my face. (The communal bathrooms may not use paper towels, just hand blow dryers)
Sharing a room with strangers has challenges; snorers, different bedtimes, and security... but all of these can be overcome!
Noise canceling earplugs & a sleep mask are great for blocking out distractions, and earphones let you enjoy music or streaming services while others sleep. (Don't be the obnoxious hosteler subjecting the whole room to your weird taste!)
