It is recommended to have some foreign currency of your destination before arriving. This will come in handy when you are looking to wake up with a cup of coffee at a nice little café after that long flight.
Invest in a neck pillow. Your neck can get kinked and sore pretty easily from trying to catch some shut eye on that long flight. There are inflatable neck pillows that are easy to deflate and will fit nicely into your carry-on after use.
Try not to nap once you arrive in your destination. It can make your jet lag worse and make you feel more tired. If possible, carry on with the rest of your day and get a good, full nights rest that evening.
Hand sanitizer is an essential for traveling abroad. Since there is sometimes a charge to use public restrooms, having a quick and easy solution to sanitize is nice and convenient, especially after a subway ride.
There is not always such a thing as “free” water at restaurants like we are use to in the states. Be sure to ask for tap water if it is available or be prepared to pay for bottled water.
Immerse yourself in the country’s culture. Try a traditional dish of paella in Spain or catch a cabaret show in Paris. There are so many things to do and see in Europe. Open your mind and enjoy!