Be sure to note the current international airline practice to book connections only 45 minutes apart. In Beijing and Miami, I found myself running between international terminals, immigration and security barely making my connections.
Be aware that even the same carrier may not arrive and depart in the same terminal, especially if you are traveling between countries or from domestic to international destinations.
The strangest delays? Having to go through security all over again when you never left the gates and being sent through immigration when you have been sequestered in a transit lounge!