It’s OK to wear the same T-shirt a few days in a row. Take half the clothes you think you will need…you won’t need as much as you think. Write down a list of essentials, cut it in half, and then only pack that! Plus, since you bought a small backpack, you won’t have much room for extra stuff anyways!
It’s always good to have a backup in case you get robbed or lose a card. You don’t want to be stuck somewhere new without access to your funds.
They come in handy, especially when you stay in dorms and need to lock your stuff up. Carry a small combination lock with you when you travel. Don’t use one with keys because, if you lose the keys, you’re screwed!
Accidents happen so be prepared. I take band-aids, antibacterial cream, and ointments for minor cuts and scrapes. You never know when you’re going to need it and you can’t always get it when you travel.
The locals will appreciate it and it will make your interactions easier. You don’t need to master the language but learning a few things like “Hello,” “Goodbye,” “Thank you!”, “Where’s the bathroom?” will go a long way to endearing yourself with the locals. They’ll like that you tried.