Food

For budget travelers, money can be tight. Grocery stores and bakeries become an important part of the trip. And that's fine. Grocery stores can provide the traveler with inexpensive local food. A carton of apple juice, fruit, maybe some Nutella (a chocolate-hazelnut spread), yogurt, whatever else looks interesting. Bakeries provide excellent bread (especially in France and Germany), as well as excellent (and often unique to the region) pastries. Turkish fast-food restaurants provide an excellent alternative to German food in Germany...and for a good price.
Experiment. Point to what you want at a local bakery...and try something new. Maybe it's a pudding-filled pastry or a roll topped with melted cheese. Maybe it's a half-fried/half-steamed roll that's big enough to fill you up. Maybe it's just a nice-looking piece of bread, ready for a big dose of Nutella.
Only once did I regret buying something from a bakery. In some small French tourist city, I ordered what I thought was a roll with cheese on top. Unfortunately, it also had some type of mystery meat and some onions inside. I ate it anyway. Within thirty minutes I was sick to the stomach. Ten hours later I (finally) threw up.
Positive experiences were much more common. These bakeries provide some of the best food available on the planet. An excellent stop for an affordable breakfast or lunch. And you're shopping how the locals shop.
The Turkish restaurants offer excellent food for cheap. They cook a huge chunk of meat on a spit, slowly slicing off the outer thin layers. They add a special sauce to the meat, and then tomatoes, lettuce, and other goodies (often to order), and either put it in a pita-bread-like container or, if you're lucky, in a soft tortilla-like shell. I ate tons of these in Germany, and I always requested "sehr scharf, bitte". "Sehr scharf?" they'd ask me, surprised that a white man would want a spicy meal. "Sehr scharf."
I have fond memories of sitting in a small French park in Paris, away from the tourists (French do a lot of things well; unfortunately, parks are not one of those things), eating incredible cheese bought from a nearby cheese store, and munching on French bread. Fond memories of trying something new at a neighborhood bakery. Fond memories of roaming a tiny grocery store, looking for cheap food to keep me full. Buying a bratwurst in a bun, topped with German mustard, or a pickled-herring sandwich, or an ice cream cone, from a street-vendor.
Sometimes, I'd even eat at restaurants. If you have a bit of extra money, this is a great place to spend it. Maybe not in England, where Pizza Hut is going to be one of your best bets (all-you-can-eat pizza). But elsewhere, authentic local food can be incredible. Get recommendations from a trustworthy source. And remember that European customer service isn't as good as American customer service. Don't let it bother you. Just enjoy the local food.
And, remember...
Be brave. It's worth it.