Different strokes .. I live in a pueblo of 1600 people. I am the only Gringo here. I like it that way. I have no interest in Gringos, especially the Lake Chapala types, tourists with furniture with a vocab limited to: How much? Wheres the beer?Â
I'm 74 and have been in MX half my adult life. If I were to pack it up I'd land in Cuba.
On forums I read over and over people rave about how nice the Mexicans are. Some are, especially the religious types.  Poverty takes its toll, not a Mexican thing, it's a poverty thing. They're opportunistic, great actors, charming, helpful, great senses of humor.  Try borrowing $ from them if you're ever down and out.
1, Learn Spanish quickly, don't delay! The language is the easy part, next comes social norms and all the courtesies.
2, Hang out with kids if you have to, their Spanish is easy, they're limited just like you.
3, Pay your own way.
4, Be generous. #1 gripe about Gringos .. they're cheap.
5, Upon arrival glue yourself to people of predominance. Avoid being seen with the trash (for lack of a better term). Like drunken bricklayers for example. But count on them being friendly.
6, If you're a man be a gentleman (Mexicans are really into that, it's called, caballerismo). If you're a woman be a lady.
7, Show great affection to children.
8, We are all from from the same culture, it's known as Western Culture. We are from different societies, boy are we ever! Read and learn.
9, Mexicans lie a lot. No need to feel guilty over it, just tell it all at confession and you'll be good with God.
10, I drink tap water 10 times a day. But I know its source.
11, If you're older demand respect and you'll get it. It's very very unnatural for a local to disrespect old folks (la gente de la tercera edad).
12, To keep the personality from stinking don't relay information, like news, with astonishment, they all have TVs.
13, Don't talk about Gringolandia unless you're asked.
14, They are akin to socialists; if you have more you should be expected to pay more. Rich, medium or poor, you'll never convince them you can't afford it. So don't bother. You're from a place where ppl earn at least 20X more, enjoy security, where about 20% have a BA/BS and just about everyone graduates from HS. The average Mexican reaches the 6th grade. No need to mention it, no need to rub it in.Â
15, The Exchange Rate: Mexicans have a habit of saying things like .. Dios mio, el dolor subio'! (OMG the dollar went up!) It didn't go up, the MXN went down. Keep it to yourself.
!6, You would be aghast at how little Mexicans know, even about their own nation. Sure, they can name more ex-presidents than you but in most matters their credo is what they learned from their mom, dad, and grandparents, all of whom had nothing to teach them.
17, La Mordida, Paying fines to the police on the spot. The hardest feature for a Gringo to accept. Not enough space here to explain why it's okay, but trust me it is okay, get used to it.
18, Mexico is advanced in many ways; Gay Rights, Marijuana, animal abuse (it's jail time here), etc. It all came to be before it did in Gringolandia. The Republic is ruled mostly by The Feds, not so much by the individual states.
19, Its kinda lawless here. Murders are not investigated unless somebody pays for the service. In our case they just call the Consulate. Once my house was broken into, I called the police, they asked for gas money.
20, Oh, let me see what could 20 be? El Grio or Chisme (gossip). Count on it, count on being the local star.