Off the top of my head:

• If possible, travel with a carry on, no checked bags. Saves a lot of time in airports and less likely losing it.
• Roll your clothes in your bag to maximize space.
• Bring a small bag/pouch for your passport, phone, keys, and wallet so you don’t have to dig through your carry on whenever you need them. You can also take it with you to the plane restroom so you don’t need to worry about someone stealing them while you’re gone.
• Save an offline map (google maps can do this, other apps can probably do too) so you dont have to worry about getting lost if you lose signal/data.
• Put your bag in front of you while sightseeing in tourist areas, in case of pickpockets.
• Always check the next day’s weather forecast to prepare accordingly.