The best way to avoid problems and misunderstandings when they arise is to protect yourself in Mexico with contracts. Reduce your agreement to writing if you are having dealings with another person. By creating a contract, each party will know their rights and responsibilities and what will be expected of them.
A few problems seem to be very common when dealing with agreements and contracts in Mexico and they are very easy to avoid.
The first problem that often arises is language. You should never sign a contract in a language you do not understand. You should always have an authorized translator and/or bilingual attorney review any important papers before signing them. Even if the document is in a bilingual dual column format, there could be important differences between the English and Spanish versions. Because Spanish is the official language of Mexico, there usually is a clause in the Spanish verbiage stating that in the event of a conflict the Spanish version will prevail.
When you do sign a contract or agreement, always make sure you sign every page. Also, ensure that there is a second original and exact copy for your files. Do not sign anything if you will not receive an exact copy of what you are signing on the spot. Make sure you come away with an original copy signed by all parties to the agreement with original signatures. In Mexico, faxes or copies are not given the same validity as an original signature. Also request a copy of the signers ID so you know whom they are and can make sure that their signature matches their ID to avoid future problems and potential attacks on the document.
Finally, remember that you need to protect your interests and not feel pressured to sign if the deal is for today only, or the seller has other offers if you do not sign right away. If there is nothing wrong with the deal, then one day should not matter. Also, do no hand over any money unless you have a signed contract. People are always glad to accept your money but getting it back from them is another matter, and even harder if you have no signed contract to explain the terms upon which you gave the money.