It may not be as nerve-racking as the interview, but it is just as important when it comes to getting a job. The odds are stacked against you, it's hard to stand out from the crowd and it's so easy to blow your chances with a careless mistake.
The application form is one of the most underrated parts of the whole job-hunting process - at least by applicants. If you are applying for dozens of jobs, it's tempting to develop a one-size-fits-all approach, believing the same qualities will be in demand at every school.
But headteachers and senior managers, faced with whittling down a pile of applications - and 80 to 100 is not unusual - into a shortlist of five or six to interview, want something else.
They're looking for the candidate who is offering something special, the one who does stand out - and not because of the bright pink covering letter.
Too many teachers are undone by what can only be described as pupil howlers, according to Richard Fawcett, a former head and past president of the Secondary Heads Association. Common mistakes include not completing the form, writing "see CV" or "see attachment" instead of answering the questions and not following instructions.
"If you disregard what you have been asked to do, people will make an inference that you will be the same in the job," says Richard, now a consultant for the Association of School and College Leaders advising on recruiting heads and senior staff.
Then there are the teachers who list their experience with the most recent last when asked to do it the other way around and those who even misspell the school's name. Richard advises against using standard letters and says one of the easiest ways to spot them is when the applicant has forgotten to change the name of the school.
Sara Bubb, senior lecturer at the University of London's Institute of Education and columnist for The TES Magazine, says the generic supporting statement is one of the biggest crimes committed by applicants. "Some people think it's a good use of their time, but the person reading it thinks you haven't made any attempt to meet their person specification. If a school has paid a lot of money to advertise a job, it's looking for someone special, not someone who can't be bothered to make an effort."
For her, the supporting statement is the most crucial part of the form, the chance for applicants to show what makes them outstanding. But too many blow that opportunity. Instead of generalisations and sweeping statements, she says heads are looking for examples and specifics.
"Everyone is going to say, 'I've got excellent subject knowledge', 'I love children', and 'I'm the bee's knees'. You have got to show in what way you are the bee's knees."
She says you should always ask for feedback if you don't get shortlisted.
Some schools will be too busy to respond to every unsuccessful candidate, or their reply may be too general to be useful, but it may help point out where you are going wrong.
Jennifer Longhurst, head of Surbiton High, a private school in Kingston upon Thames, says mistakes on forms will not disqualify a candidate but do put them at a disadvantage. She looks for teachers who have tailored their application to the school and the post.
"Your application form has to be top-notch and show just what a great teacher you are, and it also has to be relevant to the school," she says.
"I like people who have looked at our website and noticed the sort of activities pupils are involved in and tell me how they would contribute to that."
Application forms that have a page or even two for additional information need only a brief covering letter, while those with little or no space need a more extensive covering letter. Whichever form they take, these statements should be concise and sincere.
"You have to make every single sentence earn its place. I would rather read something from the heart about how the applicant loves children and wants them to achieve their dreams than a lot of jargon about personalised learning."
She says applicants will write about how they would benefit from being in the school, while heads want to hear how the school would benefit from their presence. "We're looking for outstanding teachers who are going to make an outstanding contribution to the school," she adds.
The qualities that make an application stand out are harder to pin down than the pitfalls, but Richard believes the key is to try to get something of your character across in the form. "You have to show an excellent understanding of what you're writing about, but you should also come across as a real person.
"Heads want to feel they're getting to know someone and that you're an individual who makes a contribution, so it's worth spending time on talking about your interests. You need to show something of yourself and make your application individual, rather than writing to a formula."
Next week: How to survive the interview
SEVEN STEPS TO SUCCESS
* Follow the instructions carefully - if the form says write a supporting statement on no more than two sides of A4, don't go on to a third page.
* Type your application if possible. Only do it by hand if your writing is neat and legible.
* Make sure you check all your spellings and don't rely on a spell check, it may not pick everything up.
* Back up your claims with examples. If you say you have good subject knowledge, give an example of how you demonstrated that in practice.
* Photocopy the form and practise.
* Show your draft application form to someone else - they may be able to spot mistakes you've missed.
* Try to make it as personal as possible. Give the school a picture of you as a person, rather than just a set of qualifications and experiences.
* Try to stand out by writing your supporting statement on pink paper.
* Use a standard letter where you only change the name of the headteacher and the name of the school.
* Write "Dear sir or madam". Find out the headteacher's name and write to them.
* Spill over the boxes on application forms on to separate sheets. They are that size for a reason and, unless you have something extraordinary to say which really can't fit, you should keep to them.
* Lift sentences or even whole paragraphs from someone else's application form - they may sound false and you may not be the only person using them.
* Say "see cv". Schools use forms to compare candidates more easily and, if you can't be bothered to take the information out of your cv, why should they?
* Use jargon or pad out your application by talking about trends in education, unless you have been specifically asked to discuss them.