Don't Come in the Summer
Seriously, everyone and their cleaning woman is on holiday. Turkish cities gets steaming hot in the summer months, and everyone rushes to the coast to stay in family summer homes or beach hotels. English teachers know to hoard some savings in the busier months, as income becomes unreliable once the heat sets in. Even for those on full-time contracts, work tapers off in June and picks up again in September. Those on academic-year contracts tend to go elsewhere in the summer months, for work or travel.
When we came to Turkey, we were contracted for full-time jobs starting in May, unaware of this summer work drought. Result? "Full time," well, wasn't.
Teacher/Student Roles aren't Set in Stone
Even in a huge metropolis like Istanbul, one doesn't meet foreigners often. This means we yabanjis are something of a novelty. People will be curious when you come along, and keen as beans to teach you about all things Turkey. Though you may start your first class with an iron-tight lesson plan, you'll find yourself fielding questions about your marital status, taste in movies, and favourite Turkish foods.
If you have adult students, get ready for the invites for lunch, cafe outings, and, um, dates. If you teach children, they'll hug you like they would a favourite babysitter, and expect just as much playtime.
In part, this casual amiability is cultural. Turks are endlessly social folk, and if you're looking for friends, you're in the right place. In part, the novelty of your foreign-ness might take away from your authority in the classroom. Sorry.
You MIGHT get a Work Visa
If you're keen to keep your employment history legal and legit, you'll feel duress here. Visa applications are slooow. Often, employers don't bother with the eight months of paperwork and waiting. This means border runs every three months to renew your tourist visa.
Some schools will get you a residence permit, though it still doesn't entitle you to work. It saves you the border runs, but if any authorities ask, you'll have to cook up a story about freelancing, writing a novel, or some other Vandalay Industries bit.
Know Your Grammar
Turkish students are used to rote learning, and grammar plays a big part in language learning curriculums. If you know your grammar, fantastic. If you're shaky on the technicalities, brush up on the rules and the jargon (modal auxiliaries, anyone?) If your students suspect that you don't know English grammar like the back of your hand, you'll lose your credibility faster than you can say possessive pronoun.
Need some brushing up? So glad you asked. Betty Schrampfer Azar's grammar guides are the holy books of the field.
Also, be prepared for students to throw you off your game by bringing in song lyrics with lines like "I ain't gonna hurt no more" or other grammatical minefields.
Come in Like a Lion
There's a theory of classroom discipline that a teacher should start the class as a strict, firm authority figure. Once the teacher establishes their role, they can ease up and be more buddy-like with the students. This tough first impression is essential for maintaining authority. I've never had more trouble implementing this notion than I have in Turkey. People are so friendly from the get-go, it's tough to be tough without being downright cold. Still, it's worth it, especially if you're young and/or female, up against a group of businessmen.
Once, in a class of kids, I took the time to answer all their funny questions on the first day. Authority lost. Forever. Once, in a class of adults, an alpha-dog businessman tried to dismiss the class early for cigarettes and snack breaks. I shut him down and things got tense, but in the long run, the class dynamic was a good one.