* Read the noticeboard and try to understand its code. It will transport you to places you didn't know existed.
* When you arrive at your destination, you will be flustered and the class will scent this - the game is on. They have the advantage.
* Do not be deterred by the cries of "Ooh, Miss, have we got you?", followed by (delete as applicable): "We wanteddidn't want a proper teacher."
* Some classes you have not met will insist on checking your credentials to confirm that you are a worthy opponent.
* Set work. They will deny all knowledge of ever being taught anything in this subject. They are also lying about what they usually do in this lesson.
* They do not customarily finish their work 20 minutes before the end of the lesson with their "proper" teacher.
* Exam invigilation is a special case. Be amazed at the noise clothing cn generate, particularly when hems are held up with sticky tape.
* Acquire the "exam walk", a lurching gait, to minimise the detrimental effect of your squeaky shoes on the examinees' future.
* It is vital that you eat before invigilation (see point above, but substitute noisy stomachs).
* Questions. A few pupils may need reminding that they are expected to answer them, not you.
* There will be one pupil with exam cough, a condition as yet undiscovered by the medical profession, thus "untreatable".
* Don't let your face change when you read the spare papers. Of course they'll be able to do them, that's what you've taught them, isn't it?
* Use invigilation as an opportunity to marvel at the spectacle before you, and, where possible, ask to do more. They are quiet (except the cougher). It is possible. Enjoy.
Dr Kristina Humphries is a chemistry NQT at King Edward VI high school in Staffordshire.