Sites like oDesk and Freelancer have become the bottom of the barrel and by their very nature, were always destined to become so.
If you are a professional, have solid experience and a strong set of skills, there are far better ways of finding work.
I would suggest using the job aggregator sites to start with - here's a quick action plan that should give you results:
Look for not only relevant roles, but roles that are in your geographic area - many of them have a radial search function.
Forget the adverts from recruiters - look for the ones from the employers themselves
Contact those employers directly, rather than applying for the job through the advert - a direct approach will serve your purpose better.
Let them know you are looking for freelance work and would like to be considered for not only this role, but any future roles.
Also let them know you are flexible with regards to hours, location, contract length, hourly rates, etc. - companies often have urgent roles and in those instances they will call the most flexible candidates first.
Your plan is to build relationships and contacts with as many relevant companies as possible. The more contacts you have the more frequently you will be contacted about work.
And when they do approach you, do everything you can to accept the role they offer you.
Even if the 1st role is not ideal or the salary is not quite right, take it and do a brilliant job.
By taking it you will be helping them out of a tricky situation (urgent project or problem) and I guarantee you will be the first person they contact next time.
Over time you will be building up both a network and a reputation and you will find the work will slowly get better, more interesting and better paid.
But definitely stay away from the sites you mentioned - all they are is lowest cost and lowest quality (generally)
