I was speaking with a friend about his upcoming multi country vacation, and it reminded me of some of the things I learned from my past trips that I passed along.
I was traveling to Taiwan for work, and I was lucky enough with this trip to be able to schedule in advance a stay in Japan before going to work in Taiwan, then staying in Thailand after finishing work, before flying home. My company purchased me a ticket through United going to Taiwan from Newark, and returning from Japan to Newark. I purchased my Taiwan/Thailand and Thailand/Japan tickets separately. To help me organize my itineraries, I've been using Tripit for a while now, and highly recommend it. Everything travel related is done electronically via email or an app or whatever, but when I travel I am always paranoid about my phone or laptop crapping out on me (it's never happened to me) so I make paper copies of everything, including my passport, ID's, and credit cards. Probably overkill, but I'm just an anxious traveler I guess. I throw my copies, Tripit itinerary printout, plane ticket receipts, and hotel reservations in a plastic document sleeve and throw it in my camera pack.
Getting back to my trip, I went to the business class counter to check in. I was shocked to learn that I wasn't going to be allowed on the flight because my outbound destination was Taiwan, yet I was returning from Japan. Evidently Taiwanese customs and immigration would not allow United to let me board the flight from Newark if they didn't know how I would be leaving their country. LUCKILY, my paranoia paid off for once, and United asked me for proof of my itinerary. They did not like my Tripit printout, but when they looked through all my plane ticket and hotel reservations, they were able to confirm my story and allowed me to check in.
TLDR, bring paper copies of your reservations and plane ticket receipts when you travel internationally, just in case.
If you're traveling to a country you've never been to before, I would also recommend registering with the State Department's Smart Traveler Enrollment Program, or STEP. It's a free program where you can register your trip online with the nearest U.S. Embassy or Consulate. You provide the dates and destination of your trip, your hotel and contact information, and if anything happens prior to your departure or during your trip, the U.S. Embassy will be able to get in touch with you. Now you may say I'm way too paranoid, but I was told of this program by a consultant working with me in Taiwan to does much more travel than me. While in Taiwan and Japan, I was warned of incoming typhoons via email, and also warned of government unrest in Thailand preceding one of my trips there. Nothing ever happened, but it can never hurt to let the embassy know you're in the country. You remain on the mailing lists for whatever countries you're visiting until you unsubscribe. A lot of good information when you want it.
One final recommendation for today is if you can, enroll for the U.S. Customs' Global Entry Program. If you are planning on doing a lot of international travel, there is nothing better than being able to skip a 2+ hour customs line at the airport after flying 15 hours from Hong Kong to Newark.
When I was flying enough to make Premier 1K on United, I was given a credit for the application fee, but now that I've used it I will definitely be paying for it after it expires. I think my card is good for 9 years. You even get to skip the customs line at baggage claim.
That's it for now. As I think of more things I've learned during my travels that makes things easier, I'll post them here. Any questions or comments, please leave at the bottom (login/register for private comments) or feel free to email me.