First contact with Mexican Translation executives can be by phone, but face-to-face negotiations are the way to conduct business. While your ultimate contact may speak English, remember that his secretaries may not. It is a good idea to prepare a couple of simple phrases to convey your call. While it is a mark of respect when foreigners attempt Spanish socially do not rely on them for technical or financial negations and stay away from the ugly American characteristic of talking louder and slower to someone who does not speak English.
Business people are often surprised to find that many of their Mexican counterparts speak English. However, Mexican law dictates that contracts, manuals and information sheets be translated into Spanish. This is something that many American businesses miss.
Time in Mexico can be confusing to Americans, who usually have presentations and meetings in an orderly fashion. Mexican meetings tend to wander from point to point and they do not like to be pressured due to time restraints.
Socially, it is fashionable to arrive 1/2 hour late to functions; invitations never list the departure time. Social protocol wouldn't allow it. Conversations about family, weather, Mexico or travel are acceptable especially if you have met family members. Family is VERY important in Mexico as in all Spanish speaking countries.
Lastly, remember that Mexican business runs on friendship and respect. Mexicans want to do business with friends. American businessmen should make friends with their Mexican partners, and thankfully, since Mexicans are warm, generous, friendly people, that does not take too much time south of the border.