Trial and error is a hard way to learn, especially when it comes to European travel.

How to avoid the most common pitfalls encountered by travelers to Europe

Most of us get only a handful of trips to Europe in a lifetime, so we want to get it right every time and avoid the most common mistakes. Based on our staff's daily contact with European travelers over two decades, we know what some of those missteps are. Here is our top 10:

10. Checking luggage on a European train: First, it's not free; but more important, your bags will likely not travel on the same train as you and may not arrive at the destination for several days. Assuming his luggage would be on the same train and arrive at the same time as he did, one traveler we know paid almost $25 to check two bags from St. Gallen, Switzerland to Prague. His luggage arrived three days later. It's fairly standard operation procedure. If you must check bags, find out in advance when they will arrive at their destination.

9. Failing to prepay your European rental car: Many Internet car rental websites don't require payment in advance. It's nice that you don't have to put up the money up front, but when you pay in Europe, most credit cards will assess a 3 percent foreign transaction charge. That's $30 on a $1,000 transaction. Be sure, however, when you pay in advance for your rental that the company you book with will allow you to cancel at any time, for any reason, and refund your money in full.

8. Reliance on the wrong maps: Don't think that 1:750,000 overall map of Germany or France that you got from the tourist office will be of any use when you're driving in the countryside. Some roads and some villages won't even be shown. You need a scale of 1:200,000 or, better yet, 1:150,000. Buy the proper maps - and Michelin Red Guides - for 20 percent off at Travel Essentials.

7. Buying travelers' checks: Even if purchased in foreign currency, travelers' checks are passé. It's hard to cash them outside of a bank (limited hours of operation), and the exchange is seldom as good as you'll get with your ATM card - often much worse. Our advice is to get daily cash using your ATM card. Make sure you have a four-digit PIN.

6. Paying in dollars in Europe: If a hotel, restaurant, store, or rental car agency offers the option of settling your bill in dollars, you should insist on paying in local currency. Otherwise, it will cost you an extra 3 percent to 5 percent, depending on the merchant's level of greed. Called Dynamic Currency Conversion (DCC), this new device to extract money from visitors is pitched as a "service" that enables the customer to know exactly the amount that will appear later on the credit card statement. Otherwise reputable firms such as Harrod's in London are ripping off travelers every day with this shabby trick. Pay in local currency with your credit card and let your bank make the currency exchange. You will pay the credit card's foreign transaction fee (usually 1 percent to 3 percent) but you won't be gouged the additional 3 percent to 5 percent for DCC.

5. Picking up a rental car at an airport: In Germany, Italy, Switzerland, Belgium, and Austria, the added cost of a rental commencing from an airport (and sometimes from a rail station) ranges from 15 percent to 19 percent - thus, the fee on a $500 rental can be as much as $95. Some countries charge a flat fee: Holland $75; France $37, Spain $38, and the UK $39. In many cases, it pays to take public transportation to an off-airport location to avoid the airport charge. At the end of the rental the car can be returned to the airport without cost.

4. Ignorance of Michelin's Red Guide series: No auto traveler in Europe should be without these guides. Used properly, they will take you to wonderful hotels and restaurants, both on and off the beaten track, in your price range - while providing an amazing amount of other useful information. And don't tell us they're in a foreign language; read the English section at the front of the book, learn the symbols, and you're good to go.

3. "Open jaws" that are too wide: Many travelers make the decision to fly from the United States to one European city, and home from different city, without first knowing how they'll travel between the two cities. With some vague idea of working their way slowly from, say, Rome to Frankfurt, they commit to a Rome-Frankfurt "open jaw" airline ticket. Ignoring for a moment the expense of renting a car in Italy (highest rental car prices in Europe); the international one-way charge alone to drop the rental car in Germany will be from $500 to $1,500, provided you can find a company that will allow it.

There's the train, of course, but a three-country, Italy-Austria-Germany or Italy-Switzerland-Germany pass costs two people $650, is good for only five days rail travel (additional days are available at additional cost); not very conducive to a leisurely exploration of small towns and country hotels along the way. A Rome-Amsterdam open-jaw involving a rental car is prohibitive. Just the drop charge is around $1,800, and only one company, Europcar, will even consider it. One-way rentals involving old eastern bloc cities such as Prague, Budapest, and Krakow, and cities in the west, are also expensive.

Same-country open jaws, such as Berlin-Munich, Paris-Nice, Rome-Milan, are no problem as there is usually no car rental drop charge. Others, such as Frankfurt-Zürich, Munich-Paris, and Frankfurt-Vienna have drop charges in the $100 to $150 range.

Before committing to an "open-jaw" airline ticket be sure you know how you're going to travel between the two cities in Europe - and how much it's going to cost.

2. Too many reservations prior to US departure: Unless it's necessary, avoid reservations that lock you into something you may want to change once you're in Europe. Train reservations are a prime example. First, they are more expensive in the U.S. than in Europe, and you must make a financial commitment to a departure date and time that may ultimately not be convenient. All seat reservation fees and some tickets purchased through Rail Europe are not refundable; others carry a 15 percent penalty.

Reservations are in order, however, for special trains like the Glacier Express and for long rides that commence the day of, or the day after, your arrival in Europe. For example, if you arrive in Paris on the same Saturday that you have be in south of France to take possession of a house you've rented, by all means have TGV tickets and seat reservations in hand before leaving the U.S. Watch out, too, for holidays, such as Easter, that can pack trains. And do purchase rail passes - as opposed to point-to-point tickets - before leaving the U.S.

The same applies to hotels. Book them in advance in the big cities but rely on the Michelin Red Guides when traveling in the countryside. Of course, if you want a special hotel at a special time, reserve ahead. Otherwise, one of the joys of traveling the countryside is discovering new towns and hotels along the way.

1. Trying to see too much in a short time: A classic mistake, but still widely made. If you love the process of travel- long train rides and automobile trips, carrying luggage, packing and unpacking, checking in and out of hotels, spending time in rail and air terminals, and riding in cabs, buses, and trams - by all means schedule one of those Paris-Rome-Vienna-Berlin-Krakow-in-10-days trips. But if your vision of travel is quiet walks, hours at sidewalk cafés, unhurried explorations, and leisurely breakfasts, then park the car and get off the train. Limit time in the car to two hours a day, and make your drives slow meanders along scenic backroads.