. It’s getting harder. Immigration do spot checks in schools/Uni’s and send people packing, if there are no WP’s in existence. It’s usually agency staff that get caught because of bad-practices.
The easiest job to get(& nearly the only) is English Teaching. Many jobs are restricted for Thai’s only. Get a tourist visa from your own country. Find a job, then you will have to leave Thailand to get a ‘B’ visa, then a Thai work permit. Your school/Uni should guide you with this process. It might be also worth you doing a TEFL course.