How not to look like a tourist:
1. Consult your map discretely.
2. Dress like the locals. Wear a messenger bag instead of a backpack or a fanny pack. Dress conservatively.
3. Ditch the athletic shoes. White athletic shoes are stereotypically American. Flip-flops are also very noticeable as American attire.
4. Buy accessories at local stores, especially ones that you see the locals wearing.
5. Avoid US brand name clothing.
6. Keep your camera out of sight unless you are using it.
How to live like a local:
1. Respect shared public spaces. Do not speak loudly. Remember that you are representing your country. Learn the local customs about personal space. Observe locals to know how far or how close to stand.
2. Research the sights and history of your destination. Make sure you know the basic geography, the name and rate of the local currency, language and dialects, capital city, major towns, unusual customs, and any dangers.
3. Learn the native language. You don’t need to become fluent. Even knowing a couple of words and short phrases is fine.
4. Don’t rush. Prioritize the sights you want to see and allow plenty of time.
5. Bypass tacky tourist spots and go to more interesting and authentic backstreets.
How to eat and drink like a local:
1. Go to local restaurants instead of known fast food franchises.
2. Take whatever condiments they give you. Requesting typical US condiments is a sure giveaway that you are American.
3. Give up the ice. In many parts of the world, you will be served your drinks with little or no ice.
4. Use local table manners.
5. Avoid walking down the street while eating. This is against proper etiquette in most countries.