Pack lightly. Although trans-Atlantic flights have recently reduced the amount of luggage you can check, 50 pounds is still a considerable amount if you are only going to Europe for a holiday. When packing, keep in mind that your trans-Atlantic flight won't be the only means of transportation you will use and many other services also have weight limits, such as long distance buses and inter-country flights. By packing lightly, you are potentially saving yourself quite a lot of money (and your back will thank you, too).
Watch what you eat. You went to Europe to discover the charm of the locals, and that includes all the local eating habits. Eating out three times a day can incur lots of extra costs, although when traveling, it's not easily avoided. There are things to do to make enjoying the culinary customs a little less painful for your wallet. First, enjoy the culinary customs! Don't buy the hotel breakfast. More often than not, you will be served the same food, or worse, than you can get at the local bar or restaurant for less. Observe what the locals eat for breakfast, and try to eat the same thing. Second, find a supermarket and buy fruit or granola bars to snack on later. While stopping by a cafe for an afternoon coffee can be the best part of the day, you can save lots if you only buy the coffee. Third, save the American specialties for America. A Starbucks coffee might seem like a godsend after two weeks on the go, but keep in mind that for your same particular blend that is 4 dollars in the US, in Europe you are going to pay 4 euros.