My general advice for international travel

Before you go to a foreign country:
  • Download to your phone the google translate language pack for that country, an offline gps-enabled map (that doesn't require an active data connection), and consider getting a curated local guide app.
  • Order some local currency in advance. 
  • Check with your phone carrier what they will charge you if you activate your phone in the country you are travelling in.
Before you leave for your airplane ride:
On the plane:
  • Avoid dehydration - drink lots of water; don't drink much if any alcohol.
  • Alternate between working and watching movies; don't binge on either.
  • Ask for extra water.
  • Don't eat unfamiliar food - this is not the time to experiment.
In a foreign country:
  • Eat unfamiliar food - this is the time to experiment.
  • Remember the external battery you brought on the plane? Charge it during the day in your hotel room, then unplug it and use it to charge your phone at night. You shouldn't need to plug your own phone directly into the local electricity.
  • Try to meet people your own age, both locals and expats.
  • Drink the water. Get lost. Live a little.