China is a breeze, people. After 5 years and 5 schools the only bad experiences were with summer camps.
Below is some no-brainer advice that has made my stay no more difficult than it should be.

Don't curse the students: No brainer I know but plenty of teachers do it.

Don't curse out the staff: Deal with your issues in a sensible manner. Hopefully in a similar way to which you'd do back in your own country.

Take your medication: It seems that for many, China is great place to start a fresh and go cold turkey.

Give advice but don't lecture: Many foreign teachers seem to think that local people like to have their country's drawbacks pointed out and thrown back at them at every opportunity.

Don't surrender any of your responsibility: They must get you the working visa and expert certificate but let them know that you want it back immediately after and take note of the expiry dates.

Be patient: On one occasion there was a mix-up which I didn't believe I was totally responsible for. I contacted my consulate who confirmed that I in fact was responsible. When I collected my final pay I was surprised to find that they'd doubled it. This more than compensated for the earlier loss and was in no way obligatory or expected.

Do a lesson plan: Students can tell if you've done some level of preparation and they'll thank you for it. This makes your life easier and you'll actually enjoy going to class.

My advice: Try to initially negotiate a six month contract and then renew for another six months if everything is going well. If you've done a half-way decent job they'll easily accept any amendments you suggest to the contract. Remember, the quality of foreign teacher in China is appallingly low so you have all the bargaining power.