You can either market your services directly to practices, or register with an recruitment agency. There are pros and cons either way:

Going direct is good when:

• You want to maximise your earnings
  Agencies charge a fee. By marketing your services direct to practices you can cut out the middleman, thereby potentially earning more and/or saving the practice money (making yourself a more attractive proposition in some cases).
• You are already familiar with and trust the practices you’ll be working with.
• You'd like to work in local practices to whom you can market your services easily.
• You are comfortable running your own books and paying your own tax, or have a book keeper or accountant to do that for you.

Agencies are good when:

• You want maximum financial security / safety
  Agencies bill the practice on your behalf and collect the money. You might also find it comforting that they know the practice you're going to, and someone knows you are there!
• You are new to locuming
  A spell with an agency will help you find your feet.
• You want to work further afield
  Agencies may be more likely to be able to offer you opportunities outside your local area (which might be harder for you to find).
• The practices you want to work for require locums to be sourced via an agency
  Some corporates and charities only or mainly use agency staff.

Going direct AND using an agency

• If you work directly for practices, you can find that you get booked well in advance. But people's plans change, and you can find yourself with cancellations that are hard to fill. So it can be a good idea to source work BOTH directly and via an agency. If you do this, make sure you have agreed (in writing) with the agency, which practices you will be working for direct.