Suggestions for universal clothes that blend in while traveling?

Regardless of your clothes, you will probably stick out as an American tourist. Differences in American life and diet result in different physicality, movement and habits which will be apparent to many observers. But if you want to try to blend in, once you arrive, go to a clothing store that the locals shop at, and buy the clothes you observe the locals wearing. When in doubt, solid tan, white or dark color shirts and tan or khaki pants are relatively universal, not to locals, but to travelers.

Just make sure not to wear shorts, even if you're hot. In my travels I've noticed that men in other countries never wear shorts. You can spot the Americans in shorts and sneakers a mile away. Find some lightweight pants and you're better off...Europeans wear tighter pants than Americans, in general...but I agree with Hossman, you are likely to still be identified as a tourist.

Depends where your going. Funky sneaker will do you in Europe.

Aside from dressing in attire that's more similar to what locals wear -- I sooo agree with the suggestion to avoid wearing shorts -- you can also:

1) avoid carrying around the usual tourist-y material such as tour brochures, street maps, and cameras;

2) orient yourself on a decent street map before you leave your place of stay, so you can move around more confidently, like you know exactly where you're going;

3) familiarize yourself with the local currency because it's very obvious if you're not used to a country's bills and coins while you're transacting; and

4) try not to be too obvious when you're converting the cost of local currency to US$ while purchasing things -- that's always a dead giveaway.

As a north american man living in sweltering Rome, I don't agree with all of this shorts stuff. Men are wearing shorts here, especially young men. And knee length plaid shorts at that. I don't look particularly Italian, but I get addressed i Italian and moreoever, stopped for directions, constantly--at least a few times a week. Why? because I don't carry a fanny pack--an object to be avoided at all costs.

I think its impossible not to come off as American when you travel in Europe but one way to smooth the way in most countries is to learn a handful of useful words and phrases. One of the reasons that locals can't stand tourists is because they come off as rude, often due to the fact that they don't know how to say please and thank you. Learn a few basics and people will instantly smile when you address them in their own language.
As a last note, everyone in Europe right now is an American tourist--there are hords of them on ever street, its nothing to be ashamed of, its just who you are.

Here in New Zealand, shorts are very common, especially for workmen who will wear them with big clunky boots. Travelers do often wear the "uniform" of tan cargo pants either tie-dye or alma mater top, but as long as you don't have a backpack on your back- and front-sides you can likely blend in here pretty easily wearing a wide variety of clothes.

i agree with many of the above comments. i'd also add a pair of relatively well-fitted jeans into this mix. for men, especially dark or black jeans can go a lot of places. for anyone, simple black pants of any light material. also for men, a simple solid-color collared long sleeve shirt. in general, avoiding floral patterns (ie 'hawaiian shirts') and Gap-like beige/khaki/tan whatever goes a long way. and definitely drop white running shoes.

it really depends where you're going (what country/region) and where within that place (outdoor tourist spots? operas? funky hipster bars? business-type social sphere? regular everyday walking on the street? city or village or rural?). just like in the US, dress can vary a lot depending on age, social class, location/origin, politics, etc.

I would avoid T-shirts, baseball hats and anything with an american logo especially an american college. Also if you do use a backpack, do not use a brand new one. Use one that has been well loved but avoid them if you can.

A good bet is to buy clothes there, and to wear what average people are wearing - rather than what your romantic notions put them in. India, for example is loaded with white folks wearing "Indian" garb that almost no modern-day Indians actually wear. If you're a guy, I second the "no shorts" rule and recommend a couple of light, short sleeve button-down shirts. They're really airy, usually have a breast pocket, and make you look more respectful (or something).

I totally agree: avoid wordy tees and sweatshirts. Though people do wear them (I once saw a local in Ecuador wearing an “I heart Soccer Moms” tee), it’s best to avoid them as a tourist. I’ll also add that those brightly-colored nylon jackets/windbreakers should be left at home. I don’t know if anyone even wears them anymore, but pairing one of those with your white sneakers is a dead give-away.

Don’t wear a northface fleece! It’s a dead give-away that you’re an American.