Washington, D.C. and Philadelphia

I try to avoid checking any luggage, but the airlines are getting stricter every day about the size and weight of carry-ons. So when I pack, I put any important stuff in a plastic bag and place it in a front pocket. If I'm told to check my carry-on when I get to the gate, I can just pull out the smaller bag and board.

I always bring a small flashlight to hotels in case there's a blackout. The building may not be equipped with emergency lighting, and, if necessary, my flashlight will help me quickly locate the nearest exit.

Carry the exact change for public transportation. In Venice, we were annoyed when a vaporetto (water taxi) ticket-taker refused to give us our change. Later, we discovered that if you don't have the exact fare, ticket agents make no promises about giving change.

If you take an overnight flight to Europe and early check-in at your hotel isn't an option, ask the concierge if you can store your luggage until later in the day and use the hotel gym's shower. You'll be refreshed and ready for sightseeing. Pack toiletries and a change of clothes in your carry-on.

Before leaving on a trip, I print the names and addresses of my friends and family onto clear mailing labels. (All standard word-processing programs have preset templates for creating address labels.) Then, I take the address-label sheets with me on vacation. Since the addresses are already saved in my computer and the mailing labels are adhesive, addressing postcards has become really easy.

Take along an extra duffel bag for your laundry. As your vacation progresses, throw dirty clothes into the duffel, keeping your suitcase for fresh clothes. At the end of the trip, put a tag on the bag and check it at the airport. This will also give you space in your luggage to bring home souvenirs or new clothes.

Pack light, or that great deal you found on airfare won't seem that great. On a Ryanair flight between Glasgow and Dublin, my husband and I were charged over $100 for excess baggage weight (the airline tickets themselves cost less than half that). Be sure to check the weight limits—especially on low-fare airlines—before you leave home.

I have the words "hotel" and "taxi" on my cell- phone speed dial. On a trip, I change the numbers, but leave the preprogrammed titles the same--instant access and no more little slips of paper everywhere.

On a trip to Molokai, the plane we were on was small, and luggage was crammed in every which way. At baggage claim, we noticed that someone had packed a bottle of Pine-Sol, and it had broken and leaked everywhere. Now we line our suitcases with garbage bags to protect our clothes—just in case. (It's also smart in case your bag gets left on the tarmac in a downpour.)

Lightweight, washable, and multifunctional, a cotton sarong is an easy and practical addition to every traveler's don't-leave-home-without-it bag! I've used mine as a swimsuit cover-up, as a picnic blanket on the grounds of a château in the Loire Valley, as a temporary skirt (over my shorts) in a Bangkok temple, and as an extra pillow while hiking the South Rim of the Grand Canyon. It's also handy as an airplane blanket, emergency towel, or tablecloth.

My hearing loss once made it impossible to hear any alarm clock. Then I found the Shake Awake, an alarm clock that vibrates. I no longer stare at the ceiling all night prior to an early flight in fear of oversleeping. I clip Shake Awake to my pillow or place it on a hard surface near my bed, where its rattling definitely gets my attention.

I've saved lots of money using AAA. In addition to providing excellent roadside services (help with stalled cars, lost keys, etc.), most AAA chapters offer discounted tickets to Disney World and a preferred parking pass that enables you to grab specially designated spots near the entrances. It's a dollar saver, and you don't have to walk far or take the trolley in the parks!

The best carry-on bag that I've found is a gardener's tote. It has lots of pockets on the outside and room inside for a medium-size purse, yet it's small enough to sit comfortably at my feet on a bus or plane.

We've traveled to both Mexico and China in the last year and had the same experience in both countries: When we tried to exchange dollars to local currency, the banks wouldn't take bills with graffiti on them--telephone numbers, names, doodles, anything. Nor would they accept any bills that were torn or damaged. (We noticed a group from France having the same problem with their euros.) So before you leave home, make sure that any money you plan on exchanging is absolutely crisp and clean--or better yet, ask your bank specifically for brand-new bills.

I'm a gadget freak, and I don't like to travel without things like my digital camera and iPod. On one trip, though, I put my camera down in a crowded restaurant and then forgot to put it back in my bag. By the time I remembered it, the camera was long gone. Now, I attach those kinds of items to my daypack with a lanyard. They're still easy to pull out and use, and they never get left behind.

After I was unable to locate any awards seats online for a wide selection of days and routes, I called the airline. An agent told me that the airline's Web site isn't allowed to book awards seats for its partner airlines, but agents can. Within minutes, I had enough options that I found it difficult to make a decision.

When overseas, I carry a "cheat sheet" that includes exchange rates and metric conversions. Currency conversions are available at oanda.com.

When I'm packing to leave a hotel room, I turn the bedding down to the foot of the bed so that the white sheets are facing up. This way, items placed on the bed are clearly visible. I once left a camera behind because I couldn't see it against a very dark bedspread.

Note the expiration dates of any debit or credit cards you plan on using while you're away. In Budapest, I tried to withdraw cash with my ATM card, only to find that it had expired just days before.

To ensure the studs of pierced and delicate earrings don't get damaged, I put them in a film canister. An added benefit is that they're less likely to be stolen when left in a suitcase or hotel room, because thieves presume there's nothing inside but film.

Most hotels provide cloth shoe mitts but not polish. In a pinch, a dollop of skin cream on a shoe mitt (or even a tissue) can make scuff marks vanish and leave shoes as shiny as if they'd been cleaned by a pro.

Before you book a room over the phone, peruse the hotel's site for its "Web only" rate. It's often cheaper than the best quote you'll get by calling. Recently, over the phone, I was quoted a daily rate of $129. I booked the same room online for $89.

Paramedics now look for emergency contact information in victims' mobile phones. Store the word "ICE" (In Case of Emergency) in your address book, along with the name and number of the person you'd like emergency personnel to call on your behalf. (For more than one entry, use ICE1, ICE2, etc.) Tell your friends or family members that you've chosen them as your contacts and make sure they're aware of any medical conditions or allergies that could affect your treatment.

If you know you'll be cooking while on vacation, bring along small amounts of the spices you need for your favorite recipes. You'll save by not buying large containers of spices.

Carry a twist tie in your wallet. Among other ingenious uses, a twist tie can temporarily replace a lost screw on a pair of glasses. Just peel the paper or plastic off the tie so you have bare wire, insert it where the screw once was, and twist to tighten. Unlike Scotch tape or a safety pin, a twist tie is small enough to remain hidden and strong enough to hold until you're able to replace the screw.

With two of our last three car rentals, the local branch wanted documentation beyond the standard insurance card issued by our insurance company. In San Juan, we were delayed a half hour while the agent made phone calls to verify that our liability insurance was good in Puerto Rico. In Miami, if we hadn't provided proof that our insurance covered rental cars, we would've been charged a daily collision insurance fee. Fortunately, we knew ahead of time and took a copy of the pertinent section of our policy. Our credit card included car rental insurance, but proof of that coverage was also required.

When looking for the lowest airfare, I've found that in some cases the best rates pop up when searching for one traveler instead of two. Recently, I wanted to buy one-way tickets from New York to Orlando for two people and came up with $87 per person. But when I selected one traveler, the fare dropped to $72.

Sending a flat-rate Priority Mail box costs $8.10, no matter how much it weighs or which state it's going to. After accumulating too much stuff to fit in my suitcase during a trip to Atlanta, I filled a box with laundry, souvenirs, and gifts for my grandchildren, and mailed it to my home address.

Whenever I know I'll be renting a car, I pack a couple of folded paper towels and two small spray bottles--one filled with window cleaner and the other with Rain-X, a product that repels raindrops. It's hard enough driving an unfamiliar car in an unfamiliar location. At least with a clean windshield I'm able to see properly, no matter the weather.

I bought several items while in London and noticed when I returned home that my credit card number was printed in full on each sales slip. (In the United States, usually only the last four digits of the number are visible.) Travelers should be careful when using their credit cards overseas--don't leave the sales slips lying around.