It’s Friday afternoon, and while our full-time colleagues are winding down for the weekend, we supply teachers are on the phone to peddle our flesh for the following week. Catch an agent early and you could land a nice, easy school.

A worse scenario is the early morning call-out when you are part-way through a smelly nappy crime and suddenly it’s all hands on deck for a race across the city, balancing the A-Z on your lap while trying to apply lipstick with your free hand.

Once on site, you hunt out the teacher in charge for the low-down on the day’s duties. If, like me, you’re prepared for both primary and secondary, this can vary from sauntering round an exam hall for three hours, stifling your yawns while trying to look authoritative, to a period of dreaded PE - the supply teacher’s worst nightmare. For me, leaving the security of a full-time position in London to brave the uncertainties of supply-on-demand in Leeds was an interesting step on the career ladder. As a mother with a young baby, I have found it an excellent, flexible way to make money while honing my teaching skills.

Supply teaching can be a good career opportunity when you move to a new area, as you gain first-hand experience of a wide range of schools. In other words, you soon discover those you would like to go back to - and those you wouldn’t even set foot in again.

You also find out if your discipline techniques are working. If they’re not, you can develop a range of coping strategies.

Working in many schools not only broadens your experience but provides boundless opportunities for plagiarism. Take a little book around with you and crib as many ideas as possible. This will give you a good port-folio to discuss at future interviews.

If you are flexible and prepared to teach either primary or secondary, then you are looking at a whole new field of experience and the possibility of applying for jobs in either sector.

It’s also true that longer-term supply assignments give schools an opportunity to see you in action and may lead to a permanent post. If you are supplying only a few days a week, this allows time to pursue other interests that could be an attractive addition to your CV. There is also the possibility of further study in areas such as information technology, which could enhance your overall career prospects.

Being on supply does have drawbacks. There is no opportunity to gain in-depth knowledge of subject areas or develop particular expertise. You will not build up sustained experience of a set of children and will lack the networking opportunities open to full-time teachers.

If you wish to progress from being a class teacher, then you need responsibility in areas that you cannot hope for while working on supply. And there is no access to training courses unless your agency is particularly considerate.

But, as with any career, it is the way you market yourself that determines the outcome of job applications.

Supply teaching can be a good way of finding your feet in a new area and having a foot in the door to future jobs. And I can guarantee that it will be the only period in your career when you wish that holidays were shorter.

Before striking out on the supply road in Leeds, Karen Lacy-Roberts was a design and technology teacher inLondon