By Rick Steves
Quite a few things are worth arranging while you're still at home — lining up these details well ahead of time is a big part of having a smooth trip.
Make sure your passport is valid. If it's due to expire within six months of your ticketed date of return, you need to renew it. Allow up to six weeks to renew or get a passport.
Book your international flights.
Figure out your main form of transportation in Europe: Get a rail pass, rent a car, and/or book flights within Europe. You can generally buy rail tickets as you travel, but it can be smart to reserve seats on certain trains before you leave.
Do your homework if you want to buy travel insurance. Compare the cost of the insurance to the cost of your potential loss. Check whether your existing insurance (health, homeowners, or renters) covers you and your possessions overseas.
Call your bank. Alert them that you'll be using your debit and credit cards in Europe. Ask about transaction fees, and get the PIN for your credit card. In most cases you don't need to bring European currency for your trip; you can withdraw local cash at ATMs in Europe. Note your bank's emergency phone number in the US (but not its 800 number) to call collect if you have a problem.
If you're bringing the kids, make sure you have the right paperwork, including passports, and, if applicable, letter of consent to travel without both parents and documentation for adopted children.
Make backup copies of important travel documents, including your itinerary.
Students should carry a valid school-issued ID (or consider an International Student Identity Card) to take advantage of discounts throughout Europe.
Get smart about your smartphone. Sign up for an international plan to reduce your costs, and plan to rely on Wi-Fi. Follow common-sense safety precautions to protect your phone and its data.
Download any apps you'll use on the road (maps, translators, transit schedules, and Rick Steves Audio Europe — with free audio tours of major sights and hours of travel interviews). If you like to watch videos (TV shows or movies) during downtime, download these in advance, as you probably won't be able to use streaming services overseas.
Enroll in the State Department's Smart Traveler Enrollment Program to get safety updates about your destination and to help loved ones get in touch with you in case of emergency.
Take care of any medical needs. Visit your doctor for a checkup, and see your dentist if you have any work that needs to be done. If you use prescription drugs, stock up before your trip, and pack along the prescription, plus one for contact lenses or glasses if you wear them.
Attend to your household needs. Cancel your newspapers, hold your mail delivery, and prepay your bills.
Make a list of valuables that you're bringing (such as electronics). Include serial numbers, makes, and models, and take photos of your items to serve as a record for the police and your insurance company should anything be stolen.
Check airline carry-on restrictions. The Transportation Security Administration's website has an up-to-date list of what you can bring on the plane with you…and what you must check.