9. Plan out your day and route. If you have a sense of what you are going to do and how to get there, you will be able to navigate through your day with confidence. Plan out your driving route or check public transportation maps back in your room -- not on a street corner or in the middle of an intersection.
10. Buy stuff at local stores. There may be no better place to learn a lot and fit in better than a local grocery store. Get a haircut at the local barber (this is my personal travel custom), or buy your lunch from a food cart.
11. Move counter to the crowds. Folks who really want to blend in with the locals also tend to want actually to go out and be with the locals -- and following the well-worn tourist tracks won't get you there. If you visit the Liberty Bell, you should expect to be surrounded by other tourists visiting the Liberty Bell. This advice is applicable to almost everything you do -- so try staying somewhere other than the popular tourist hotels, going somewhere other than the most popular tourist beaches, and seeing some of the more unusual or out-of-the-way sights (which can still be found in tourist guidebooks and websites).
12. Learn -- and use -- some of the language. Arguably mangling the local language just makes it clear you aren't from around here, but you would be surprised how much slack you get for trying. If you don't know how to say something, ask -- many locals are happy to help you learn. And the more you practice, the better you get at the language, which can open doors that lead you deeper into the local culture.
13. Say hello. At the very least, say hello to folks you encounter. You would do this at the local Wawa, so you should do the same at the panaderia.
14. Modulate your voice. Don't be the obnoxious American in the corner booth whose loud laughter disrupts everyone else's dinner. It's not like people in other places are quiet -- every neighborhood has a local or two who is really noisy -- but that person shouldn't be your role model if you're trying to blend in. (Some travelers recommend you speak at about half your usual volume.) Keep in mind that there are exceptions to this rule, though; in some cultures and settings (like a noisy public market), you'll need to speak up in order to be noticed and fit in with the locals. Also on this topic: If you don't speak the language, talking even louder in English is not going to make you understood. Volume does not equal comprehension. Lower the volume!
15. Be a prepared and attentive driver. Nothing screams "outsider" like someone stopping and starting, going under the speed limit, gawking out the windows, and generally clogging up the streets and roads. Try to check your maps and route ahead of time, put someone in the copilot's seat who has a handle on it, and most of all watch the road ahead of you.
16. Pay attention. If you want to blend in with the locals, pay attention to how the locals act, what they do, where they congregate, how they dress -- and follow suit. If you want to walk the walk, it's going to have to be their walk. And don't assume that your custom is their custom. If you are paying attention, you might find that things like prolonged direct eye contact or a giant smile don't go over too well in a particular location, even if at home these are always the way to go. Change up your style to match their style as you go along, accepting that you won't get it right immediately.
17. Carry yourself with confidence. Locals tend not to walk wide-eyed around their own neighborhoods. Look like you know what you are doing and where you are going, and other people will think you do -- even if you don't have a clue.
18. Consider alternative lodging. A homestay or an apartment rental in a residential neighborhood will give you more of an opportunity to interact with locals than staying in a hotel in a touristy part of town.
19. Look for local events. Check out fliers and local entertainment listings to find concerts, festivals, lectures and other events that will attract locals rather than tourists (universities, libraries and churches are good places to look for this sort of thing). Senior Editor Sarah Schlichter recalls, "I once pushed aside my afternoon sightseeing plans when I stumbled upon a free organ concert in a Rotterdam church, and it ended up being the best memory I had from my time there."
20. Be yourself. There is only so much you can do to make yourself disappear into the local culture. When I was in Beijing, I could have worn a dragon costume in a street parade and I still would not have been able to blend in. But I met a lot of great people merely by saying hello and being myself from there on out; if I had tried to be too cool, it would have been a far lesser experience.
If you employ enough of the tactics listed above, don't be surprised on your next trip if someone asks you for directions in a language you barely understand.
The Independent Traveler