Exercise your pet before the flight so it will be more relaxed and tired this will help it to remain calm in the kennel.
Pets might travel better on an almost empty stomach. You may want to discuss feeding with your vet.
Arrive at the airport with enough time to relieve your pet. Be sure to bring a bad to cleanup if necessary.
Properly label the kennel - Federal regulations require that each kennel be properly labeled with the words "LIVE ANIMAL" on the top and at least 1 side of the kennel in 1" letters. Also, the kennel must have orientation labels on at least 2 sides.
Never give your pet tranquilizers or sedatives unless under a veterinarian's direction.