Plan ahead. Booking late can sometimes land good deals, but it's always good to plan ahead. Check which periods are peak and off peak for your destination. Try to travel during off-peak periods for better deals. Have a budget when planning your travels. Consider hostels or even capsule hotels to save money!
Write down or take a photo of the addresses of the places you're staying at and going to. Sometimes you might not have access to your email. Also let you family know where you're staying. You can also download a copy of an offline map of a specific area in Google Maps so you're not always reliant on having access to the Internet to navigate.
Pack a pen in your bag that you take on the plane. You might need one to fill out an arrival form for customs on entry to a country.
Bring a power bank. When you're on the go the whole day, and using your phone a lot to navigate, the battery can drain quite quickly.
Don't pack all of your money in one place, in case you lose it.
Pack light. It's easy to overpack and bring too much that can weight you down. Bring only what's necessary. Remember you might need space in your bag for anything your plan to bring back like souvenirs. Many airlines charge for checked or even carry-on baggage now. Consider that when you're packing.
Buy travel insurance. It's best to be prepared for the unexpected as medical expenses can be high abroad. Some credit cards have some travel insurance coverage, check what your card covers.