For those who have received a TEFL certification, do you have any tips for those just starting out?

[vitojohn]

I'm about to graduate with my Bachelors in about 4 weeks. I'm considering getting a TEFL certification post-graduation and traveling around for a while teaching English. I feel it would be both a great way to impact the lives of others, while at the same time being able to travel and experience other cultures. I'm still very fresh to the concept, though, so I was wondering if I could pick the brains of those who already have/already are working this route.

For those who have experience in TEFL, what did you learn that you wish someone would have told you before you started? If you could go back, would you choose this same route all over again? What tips would you give someone like me, who is at the very onset of this path?