Remember that agencies get a lot of feedback from their clients, so you need to be a good and punctual worker to get continuous offers. Another good source of jobs is magazines that can be picked up free from paper bins in the major tube stations of London. You'll need to get them early and start making phone calls on the day they are published because these jobs can go quickly. You can also look in the daily newspapers for a list of recruitment agencies.

Remember that the working holiday scheme is supposed to be incidental and should not use up more than half of your trip. You should also not engage in work that resembles your career back home, otherwise you run the risk of being deported.