As you are probably well aware of there are a multitude of schools, including universities, and English training centers abroad which just require you to be a native speaker in order to teach non-native speakers. I would urge you to speak to a current student or graduate of the TEFL course you wish to attend to get a better idea about this specific program. Use your best judgement as far as the professionalism encountered there goes and if it is worth what they would be charging you: check out their web site and if you can't find one, that would be a clue to heed.
I believe that a good program would require you to already be proficient in a foreign language, instruct and advise about teaching methodologies, learning strategies, educational pyschology, cross-cultural communication and culture shock, and curriculum preparation in addition to providing supervised opportunities for student teaching, hopefully with a target audience reflecting the country or region you would be teaching in.
As far as how to teach non-native speakers, keep in mind that all educators should keep in mind the concept of (n + 1), where the variable represents your students' proficiency level: teach one step above what your audience is capable of handling. That gives them room to grow. My advice to you is that you never use the students' native language in or out of the classroom while around them as this does not promote communication in the target language.
After you acquire work experience, you should expect your salary to rise. As GiddyGad pointed out, with more teaching experience both in and out of the physical classroom, you will be able to implement pragmatic applications of the theoretical knowledge you have learned during your training: proper preparation is worth its weight in gold. Realistically, I have seen non-native speakers with a high profiency level in the target language and proper training be selected against native speakers who did not have educational training. Nevertheless, I have unfortunately also witnessed employers abroad that wield racial discrimination and would never hire a non-native speaker or someone whose skin color or appearance was not marketable.
My experience has also taught me that the cultural expectations for teaching methodologies and just how a class should operate differ depending on which region you find yourself in. My advice would be to use the target language's culture so that you could prepare your students to successfully study or work in a location where the target language was the medium of communication: I teach two languages and I use different methods depending on which language I am teaching to be able to provide a more authentic experience for my students.
Eric Paul Monroe