In general the qualifications to teach are a degree and a TEFL certificate. However, if you are there in person you can often find work by visiting the schools in person, introducing yourself and leaving a CV. If they need a teacher they will get back to you. This may result in working a few hours in several different schools but in time you can build up a good job like this.

Also, it will depend on where you move. The link below will take you to some information about TEFL in South America where you can read about individual countries and their requirements.

An alternative, of course, is to advertise your services locally and teach private lessons. The pay is often slightly better although it's less secure.