Put your list of recruitment agencies on an Excel spreadsheet and include information such as website details, phone number, email and contact history.
You may decide to email all the agencies on your list or selectively choose your most important contacts to email. Remember sending your CV is quite often not enough. If you have not been contacted by the agency than a follow up call is necessary. Develop a relationship with a consultant at each agency so that they think of you first when a suitable vacancy arises.
Register with three to five agencies in the first week.
Make a decision after the first/second week whether you feel you should register with more agencies.
Weekly routine
If seeking temporary work contact the agencies you are registered with weekly. If you are seeking permanent work do this every two weeks. The idea is to keep you in their minds.
Look through all the recruitment agency websites that have job boards to see if they have any new suitable vacancies advertised.
Depending on the response you receive you may wish to register with additional two to three recruitment agencies a week. Obviously if your response is good this may not be necessary. This is a judgement call by yourself not a rule.