How well can you tolerate hot weather?
What type of environment do you want to live in?
How would you like to get around town?
What will your monthly budget be?
How do you feel about learning Spanish?
How close do you want to be to the U.S./Canada?
How much time will you spend in Mexico?
What do you like to do in your free time? Pick your top 3.
What kind of community are you looking for?
Which describes you most?
How important is culture to where you live? (i.e., museums, art galleries, ethnic food, festivals)
Why are you planning to retire to/move to Mexico?