As upsetting as it is to lose a paper doll in your house, losing one while traveling is much worse. Ideally I should have posted this before the winter holidays when most people are planning holiday trips, but better late than never. This list is written with airplane trips in mind, but I hope it will be useful to you even if you choose to travel by other means.
1. Never take your favorite doll with you. This may seem strange, but look at it this way - would you be willing to risk your doll getting lost? I'm a firm believer in Murphy's Law, and I know firsthand how awful it is to lose your favorite doll. If you want to take a doll, think carefully about how you would feel if it was lost, and only take it with you if you don't mind anything happening to it. And don't take too many dolls, either. Each doll you take means another doll that could potentially get lost.
2. Don't take it out on the plane/other means of transportation. Not to be morbid or paranoid, but that increases the likelihood of something happening to it. Paper dolls are feather-light, so it's easy to forget you have one in your lap and accidentally drop or lose it. I know how much fun it is to share the trip with a doll, but that fun isn't worth the heartbreak when you get off and realize that you left the doll behind. Some readers will say that if you watch your doll very carefully everything will go fine, which is true. But do you really want to take the chance?
3. Keep your doll in one place only. Like in yesterday's post, you need to set up an area for your doll, only you need to be stricter when traveling. If you're not playing, the doll should be in X. If the doll isn't in X, it should be with you. When you're not home, you can't forget about a doll for a week or two and then suddenly remember that you lost it. And while you're at it, make that area a pocket in your suitcase or something that will be coming home with you (though not in a clothing pocket; you don't want to run the risk of accidentally putting your doll through the wash) as opposed to a bedside table or something like that, to ensure that the doll will come home safely.
4. Don't bring a lot of stuff. Again, the more you bring, the more likely that something will get lost. A few (no more than 3) outfits and an accessory or two will be plenty.
Sorry to sound bossy and paranoid, but after years of traveling with (and, unfortunately, losing) dolls, I don't take chances.
Good luck with your future travel plans, and have fun on your next trip!