When traveling abroad, you are a representative of your country. Like it or not, you are judged based on your appearance and interactions, and your perception will either fuel or help dispel cultural stereotypes.
“Doing as the Romans do” is extremely important, not only because it is the right thing, but it also has many practical consequences. When you blend in with the local populace, you both reduce your chances of being pick-pocketed and being turned away at restaurants, as well as increase the possibility of meeting new people and gaining entrance to places you might not otherwise.
Europeans, for example, on average do not have the same fear of dressing as the majority of American men. Instead, they rightly see it as another means of self-expression. Disregard of appearance is seen both as a lack of respect for self as well as others.
Unless you are traveling to Cancun, ‘vacation’ does not always inherently mean t-shirts, shorts and sandals. When traveling to a foreign city, it is important to always be presentable and give the same attention to detail you would for a first date.
Certain things are a dead giveaway that you are an American tourist. Principal among them are cargo pants, non-ironic American flag shirts, rumpled clothing, and torn jeans. Chinos are another item that, while popular in the U.S., are basically nonexistent in most European countries.
The best way to go is to wear understated clothing in neutral colors. Clothes from European labels such as A.P.C. are great because they are pegged to the fashion in Europe rather than stateside.
A fail safe packing list, which can be modified for the duration of your trip, would include bringing at least one stylish blazer, which is imperative for access to upscale restaurants. Also plan on bringing at least a few dress shirts for daily wear; ties are up to personal discretion and style. For jeans, think about what you might wear to the office on a casual Friday; if they are ripped or baggy, leave them at home to wear while painting the house.
Obviously, if you plan on sightseeing and extensive walking (which is the best way to really see a city), it’s important to bring comfortable shoes, though this does not necessarily translate to sneakers. While living in France, I remarked that almost everyone from the age of fifteen up wore loafers or proper shoes rather than sneakers. There, nicer restaurants and bars will not allow people in sneakers to enter. Packing one pair of black and one pair of brown shoes will likely be all you need for your travels.
If you follow these simple guidelines, you will have little reason to fear being targeted or labeled as an unwelcome tourist and anything that can diminish the prevalence or necessity of fanny packs is a very good thing.