1. You may be on the right train, but are you on the right car? Always check the outside of the train car you’re riding in to make sure it’s actually going to your destination. Sometimes trains decouple and split off in different directions.
2. Sometimes - especially during high season - it's worth the extra money to buy a 1st class ticket for regional trains that don't require seat reservations, or you might be standing in the aisles for a long time.
3. A 1st class Eurail Pass is not available to one person traveling solo. Only for two or more people traveling together.
4. In many train stations, buying a rail ticket at an automated ticket machine is cheaper than buying it at the ticket counter.
5. Use the bathroom before you get off the train. It's free.
6. Bring your own food, snacks, and drinks on the train. It's less expensive than the dining car.
7. When riding a night train across international borders, try not to panic when the train conductor takes your passport for the night. They'll give it back.
8. If you have a single country or multi-country Eurail Pass but wish to travel through a country where your pass is not valid, you will have to pay for the leg of the trip through that country even if you don't stop or change trains in that country.
9. If you find a compartment train car, enjoy it - they won't be around much longer.
10. Train stations in Europe are great resources for tourist information, city maps, currency exchange, inexpensive food vendors, and (sometimes free) bathrooms.