Before you can start convincing companies to hire you on oDesk or Elance or Freelancer or wherever to do whatever it is you do, you need to make sure you put in the time to do all these things in your profiles.
Be the client.
Before you start your profile, you have to put yourself into the mindset of someone who will be looking to hire you. People want to know what’s in it for them when they spend money, so be sure to hint at how clients will benefit from choosing you.