So if you're carrying a lot of film, get to the airport early. Take your film out of the cans, and pack the empty cans in your checked luggage. On the return trip, this strategy also makes it easy to see which rolls you've shot. If you're traveling by car in hot weather, pack your film in a small white Styrofoam cooler. Don't ever let go of your camera bag.
Cameras are a favorite target of thieves.
Always have the shoulder strap on, or at least keep your hand directly on the bag. Don't let your guard down, even for a second. Store your camera under the seat. On airplanes, the contents of overhead common bins tend to get shoved around quite a bit. Keep your film cool.