Have a water bottle, pair of sunglasses, and keep aware. Also, have proper footwear. Most people don't have a good pair of shoes in their day-to-day, but you really do need them when you are traveling. I have seen so many bloody heels and hurt toes because people are walking long distances in bad shoes. It is madness.
Bring water and a scarf. Ideally a multi-purpose scarf that can be used at the beach, as a face cover, as a spare cover-up or handkerchief. I promise it will be practical especially if you're a seasoned traveller. You're going to experience different weathers at a constantly wild pace. Bring medicine as well! Get your shots and bring headache and colds medicines-- it will help if you're still adapting to the climate of the country.
Mine are as follows: 1) Always keep your valuables in your front pockets. 2)Remember to bring a translator with you. 3) Remember to keep your passport in a safe place where ever you might be staying at.
1. Don't ever leave your things out of your sight. It's so easy to get your luggage stolen as criminals from other countries know tourists aren't as "smart" about said country. 2. Make a list of everything you want to see, and where the place is. This is good if you don't want to miss anything, and also some places might be closer to each other than you think. 3. Book your flight early on, so you get the best prices.