Every seasoned traveler knows how important it is to be acquainted with the customs and ways of a country he/she will be visiting. Because not everywhere they have the same way of living as you're familiar with.
So because of our upcoming trip to Argentina, I've been spending some hours a day lately to read as much about the country as I possibly can. Well, the general things remain the same: don't flash your (expensive) smartphone, don't wear costly jewelry, and take care of your purse and credit cards.
We've been to South America before (Peru and Bolivia) so we know to take care of pickpockets. One member of our group got robbed of his expensive camera and I lost my gold earrings. Nowadays I travel without earrings and just take along some cheap ones (2-3 €) to wear for dinner. We also take along an old-fashioned phone (of some ten years ago) in which we put our SIM card. It still works and in time of need you can make a phone call. Credit cards and ready cash we always try to put in a deep pocket, so we don't need a handbag. That way you don't look like a tourist at first sight. We equally have an old camera (still in working order) so we can take pics but don't need to be afraid someone will be wanting that old junk!
For the rest, mostly it's only common sense. By trying not to be a tourist at first sight, we've visited many places and never been robbed of anything. Once a lesson learned...
What I haven't done is taking lessons in Spanish. Both my sister and I know some elementary vocabulary from earlier trips to Spain and anyway, they don't speak quite the same in South America. I had a student from Venezuela some years ago, and she has told me a lot about the difference in pronunciation. We're quick though to pick up local speech, and it won't take too long before we can order our food in what counts for Spanish, or ask for directions, etc.